Comprehensive Physiology Wiley Online Library
Home Browse Topics Latest Issue All Issues

Central Control of Nociception

Full Article on Wiley Online Library



Abstract

The sections in this article are:

1 Pain and Its Measurement
2 Primary Afferent System
2.1 Fiber Systems Signaling Sensory Pain From Skin, Muscle, and Viscera
2.2 Neurotransmitters in Primary Afferent Fibers
3 Neuronal Circuitry Mediating Nociception
3.1 Spinofugal Projection Systems and Intrinsic Spinal Circuitry
4 Neurotransmitters and Integration of Nociceptive Information
4.1 Amino Acid Neurotransmitters
4.2 Monoamines
4.3 Neuropeptides
5 Opioid‐Induced Analgesia
5.1 Opioid Actions on Central Neurons Signaling Sensory Pain
5.2 Mode of Action of Opioids
5.3 Actions of Naloxone
6 Pain Modulation Triggered by Peripheral Mechanisms
6.1 Activation of Low‐Threshold Receptors
6.2 Acupuncture
6.3 Transcutaneous Nerve Stimulation
6.4 Activation of High‐Threshold Receptors
6.5 Stress‐Induced Analgesia
6.6 Analgesia Evoked by Hypnosis
7 Pain Modulation Triggered by Central Stimulation
7.1 Dorsal Column Stimulation
7.2 Stimulation of Descending Pathways
7.3 Monoaminergic System and Stimulus‐Produced Analgesia
7.4 Opioid‐Induced and Stimulus‐Produced Analgesia
8 Epilogue
Figure 1. Figure 1.

Conceptual model of sensory, motivational, and central control determinants of pain. Output of T (transmission) cells of gate control system projects to sensory‐discriminative system and motivational‐affective system. Central control trigger is represented by line running from large‐fiber system to central control processes; these, in turn, project back to gate control system and to sensory‐discriminative and motivational‐affective systems. All 3 systems interact and project to motor system.

From Melzack
Figure 2. Figure 2.

Schematic illustration of different peptide systems in spinal cord of rat. At least 4 different types of neurons can be recognized. 1: Peptide neurons descend from brain, terminating in various parts of gray matter. Dotted lines, hypothetical projection. 2: Primary sensory neurons, with cell bodies in spinal ganglia, terminate in dorsal horn. 3: Local spinal interneurons or propriospinal neurons, with cell bodies in dorsal horn or in other parts of gray matter (not shown), terminate in dorsal horn. 4: Neurons in sympathetic lateral column (or in parasympathetic intermediolateral column) project out from spinal cord to periphery. Note that coexistence of peptides with classic transmitters, such as catecholamines and 5‐HT, is not indicated here. Abbreviations denote peptide against which antiserum was raised: ANG II, angiotensin II; APP, avian pancreatic polypeptide; CCK, cholecystokinin; ENK, enkephalin; NT, neurotensin; SOM, somatostatin; SP, substance P; TRH, thyrotropin‐releasing hormone; VIP, vasoactive intestinal polypeptide.

From Hökfelt et al.
Figure 3. Figure 3.

A: schematic indicating location of Rexed's laminae from segment L7 of cat spinal cord. B: course and destination of afferent fibers from dorsal root to dorsal horn. Afferent fibers: 1, muscle spindle afferent; 2, hair afferent; 3, touch corpuscle afferent; 4, Aδ‐afferent; 5, C afferent.

A adapted from Rexed ; B from Wall
Figure 4. Figure 4.

Spinothalamic tract cell in primate with wide‐dynamic‐range receptive field. Cell was located in lateral portion of neck of dorsal horn (A). Receptive field included area sensitive to low‐intensity mechanical stimuli (black area in B), surrounded by area requiring higher‐intensity stimuli (hatched area). Cell was excited by hair movement (C), pressure (D), and pinch (E). Pinch was most effective stimulus. Temperature changes from 35°C to 50°C (F) and from 20°C to 10°C (G) excited cell. Lower traces in F and G are records of temperature at thermode‐skin interface. Time scale applies to C‐G.

From Chung et al.
Figure 5. Figure 5.

Viscerosomatic convergence in spinothalamic neuron of monkey (T12 segment, lamina V). A: responses to squeezing skin of flank, distension of urinary bladder (60‐ml volume injected rapidly), and manual compression of exposed ipsilateral testicle. B: summation of responses to distension of bladder (80 cm H2O) and squeezing skin of flank. C: reversed sequence of B.

From Milne et al.
Figure 6. Figure 6.

Reciprocal sensory interaction. Scheme to illustrate possible interactions among dorsal horn and substantia gelatinosa neurons, leading to reciprocal interaction between afferent inputs from mechanoreceptors and nociceptors. SG, substantia gelatinosa neurons as classified by Cervero et al. ; 1, 2, 3, and Th, classes of dorsal horn neurons according to Cervero et al. .

From Iggo
Figure 7. Figure 7.

Summary diagram of terminal and perikaryal immunoreactivity of glutamate decarboxylase (GAD) and peptide‐containing interneurons. ENK, enkephalin; SUB P, substance P; SOM, somatostatin; APP, avian pancreatic polypeptide; NT, neurotensin; 5‐HT, 5‐hydroxytryptamine. Perikarya with proximal dendritic segments illustrated against background of stipple, which indicates distribution of intrinsic peptide or GAD + terminals.

From Hunt et al.
Figure 8. Figure 8.

Diagram of neural systems important in pain and pain modulation. Small‐diameter nociceptive afferents (S) and larger‐diameter nonnociceptive fibers (L) activate spinal mechanisms leading to generation of impulses ascending to higher centers. Neurons in ventrobasal thalamus [ventralis posterolateralis shown here (VPL)] receive input from fibers of dorsal column‐medial lemniscal system and from that portion of ventrolateral spinal cord forming spinothalamic tract. Projection of these neurons to somatosensory (som sens) cortex provides basis for discriminative aspects of somesthesis, possibly including pain. Other fibers ascending from ventrolateral spinal cord send projections into brain stem reticular formation (RF) and to medial thalamus. Ascending reticular formation fibers also project to medial thalamus and hypothalamus (hyp), where they may influence limbic forebrain mechanisms subserving motivational and affective components of pain. Both discriminative and motivational‐affective systems are modulated by descending pathways acting at thalamic, brain stem, and spinal levels.

Adapted from Casey
Figure 9. Figure 9.

Responses of high‐threshold somatosensory area I cortical neuron (monkey) to mechanical and thermal stimuli. A: receptive field location was confined to glabrous skin of hallux. B: location of recording site was identified to be in layer 4 at junction between areas 3b and 1. C: peristimulus time histogram of responses to graded series of mechanical stimuli. D: film records of action potentials before (upper trace) and during (lower trace) noxious heat pulse from 35°C to 50°C. E: peristimulus time histogram of response to noxious heat pulse (time course of temperature indicated above abscissa). Bin width was 1 s for all peristimulus time histograms.

From Kenshalo and Isensee
Figure 10. Figure 10.

Schematic illustration of sections through rostral medulla of rat and cat. Several structures are indicated, each of which probably exerts control of spinal nociceptors: NRM; nucleus reticularis gigantocellularis (Rgc); nucleus reticularis gigantocellularis pars α (Rgc α); nucleus reticularis magnocellularis (Rmc); probable rat analog, nucleus reticularis paragigantocellularis (Rpg); and more lateral nucleus reticularis paragigantocellularis lateralis (Rpgl). Serotonin‐containing neurons are found in NRM and in Rpgl but not in Rmc or Rpg.

From Basbaum and Fields
Figure 11. Figure 11.

Effect of intravenous morphine on wide‐dynamic‐range neuron in dorsal horn of rat. Poststimulus histogram [50 trials; time base (TB), 5 ms] of responses induced by stimulation of sural nerve (16 V; pulse duration, 1 ms). First component related to Aα‐input is truncated; only discharges related to Aδ‐ and C‐fiber inputs are considered. Length between nerve‐stimulating electrodes and recording site in cord was 18 cm.

From LeBars et al.
Figure 12. Figure 12.

Ratemeter recording of wide‐dynamic‐range neuron displaying depressant response to microiontophoretic application of Met‐enkephalin (M‐Enk). Depressant effect of M‐Enk on this spontaneously active neuron was antagonized by prior iontophoretic application of naloxone. Recordings are continuous, and drug applications are indicated by horizontal bars; ejection currents (subscripts) are given in nanoamperes (10−9 A).

Adapted from Zieglgänsberger and Tulloch
Figure 13. Figure 13.

Schematic diagram illustrating hypothesized (enkephalinergic) control mechanism of neurons in substantia gelatinosa over multimodal neurons involved in somatosensory perception. Small bipolar (enkephalinergic) neuron impinges together with afferent large‐ and small‐diameter fibers on dendrites of laminae 4 and 5 cells carrying opiate receptors (dots). Inhibitory interneurons (IN) have postulated to make C‐fiber input to bipolar neurons inhibitory (see ref. ). Descending pathways can act directly, e.g., via noradrenergic, dopaminergic, or serotonergic pathways, on neurons of spinothalamic system (L4 and L5) or via enkephalinergic neurons in substantia gelatinosa (only this part of descending influence would be sensitive to opiate antagonist naloxone). Presynaptic contact is marked with question mark. +, ‐ Represent excitatory and inhibitory influences. SOM indicates possibility of primary afferent inhibition by somatostatin. This inhibitory‐acting neuropeptide was demonstrated in primary afferent small‐caliber fibers (see ref. ).

Adapted from Zieglgänsberger and Tulloch
Figure 14. Figure 14.

Different types of descending inhibitory influences in dorsal horn. A: encoding of intensity of noxious skin heating in single dorsal horn neuron as affected by stimulation in periaqueductal gray (PAG) and mesencephalic lateral reticular formation (LRF). B: location of stimulation sites in midbrain.

From Carstens et al.
Figure 15. Figure 15.

Increased spontaneous firing and enhanced nociceptive responses of lamina V neuron after naloxone administration. Neuron was excited by alternately heating glabrous skin of left hindpaw above 45°C and deflecting adjacent hairs by a moving air jet. Responses remained enhanced for >20 min after administration of naloxone, 0.5 mg/kg iv.

From Duggan and Johnson
Figure 16. Figure 16.

Increased reflexes and excitatory postsynaptic potentials (EPSPs) recorded in motoneuron after administration of naloxone, 0.1 mg/kg iv. Reflexes were recorded in S1 ventral root. Intracellular records were obtained with 1.2 M potassium citrate‐containing electrode. A: responses to electrical stimulation combined medial and lateral gastrocnemius nerves (MLG) with stimulus strength 1.5 times threshold for fastest‐conducting fibers. On reflex records, arrow marks timing of nerve stimulus. On intracellular records, stimulus coincided with the trailing edge of 2‐mV calibration pulse. After naloxone, neuron fired to each nerve stimulus. Upward arrow indicates that upper part of each action potential was clipped by amplifier gain used to record the much smaller EPSP. B: responses to stimulation of tibial nerve with stimulus 3 times threshold for fastest‐conducting fibers. Timing of stimulus as outlined in A.

From Duggan
Figure 17. Figure 17.

Effects of diffuse noxious inhibitory control evoked from various parts of body by noxious pinch (period of pinch arrowed) on response of convergent neuron to regular light stroking (dots) applied every 10 s.

From LeBars et al.
Figure 18. Figure 18.

A: inhibition of responses of wide‐dynamic‐range spinothalamic tract cell of monkey to stimulation of A‐ or C‐fibers of sural nerve by descending volleys initiated by stimulation in nucleus raphe magnus (NRM). Histograms in A and C show control responses to stimulation of A‐ and C‐fibers, respectively. Inset in C is C‐fiber volley recorded from sural nerve. Stimulation in NRM during times shown by bars in B and D (150‐μA pulses at 333 Hz) inhibited responses. E shows location of stimulating electrode in sagittal section at midline of brain stem.

From Gerhart et al.
Figure 19. Figure 19.

Inhibition of high‐threshold spinothalamic tract (STT) cell of monkey by stimulation in NRM. A: response of cell to electrical stimulation of skin and inhibition of this response after stimulation in NRM (10 50‐μA shocks at 333 Hz). Inhibition (as percentage of control response) increases with increasing stimulus strength (10 stimuli) (B) or with increasing numbers of stimulus pulses (100 μA) (C). D: location of STT cell. E: receptive field. F: location of stimulation electrode. RM, nucleus raphe magnus; VII, facial nucleus. G: time course of inhibition (stimulus‐train duration indicated by solid bar at bottom).

From Willis et al.
Figure 20. Figure 20.

Inhibitory postsynaptic potential (IPSP) evoked in spinothalamic neuron by NRM stimulation. Antidromic spike in A resulted from stimulation in contralateral ventral posterior lateral nucleus of thalamus. For this record, calibration bars at center bottom represent 20 mV and 2 ms. Spikes in B are background discharge of impaled cell. Stimulation at point indicated in inset in C inhibited background discharge. Stimulus‐train parameters for this and remaining records were 100‐ms train of 0.1‐ms pulses at 333 Hz and 200 μA. Calibrations: 20 mV, 20 ms. The IPSP in D was recorded with DC‐coupled amplifier. Hyperpolarization outlasted sweep, as shown by comparison with reference trace. The NRM‐train duration indicated by horizontal bar under record in this and following traces. Calibrations: 2 mV, 50 ms. E‐H: IPSP during passage of graded amounts of current through acetate‐filled microelectrode. I: field potential evoked by same NRM stimulus when micro‐electrode was just outside cell. Calibrations: 2 mV, 20 ms.

From Giesler et al.
Figure 21. Figure 21.

Schematic representation of system employed for superfusing in situ spinal cord of anesthetized rat. Polyethylene 10 (PE 10) catheter used for infusion is inserted through cisterna magna to caudal level of lumbar cord. Outflow cannula is placed into cisterna magna. Artificial cerebrospinal fluid is perfused at rate of 100 μl/min and collected by withdrawal syringe and iced sampling tubes. Modification of release from spinal cord is achieved in this schematic by placement of electrode into raphe magnus. In other experiments, microinjection cannulae were placed into periaqueductal gray.

From Yaksh and Hammond
Figure 22. Figure 22.

Release of serotonin and norepinephrine into spinal cord superfusates of 2 representative rats after electrical stimulation of nucleus raphe magnus. Left: sites of stimulation indicated on coronal sections of medulla by black circles. After collection of 25‐min sample of superfusate to determine basal efflux of serotonin and norepinephrine, raphe magnus was stimulated at 25 Hz with 0.5 ms square‐wave pulses of either 150 or 250 μA for 25 min. During stimulation, another sample of superfusate was collected to determine release of serotonin and norepinephrine evoked by raphe stimulation. Quantitation of amines was by high‐pressure liquid chromatography with electrochemical detection. Right: release of serotonin (5‐HT) and norepinephrine (NE) expressed as ng/ml superfusate under basal conditions (B; open bars) and during stimulation of raphe magnus (S; stippled bars).

From Yaksh and Hammond


Figure 1.

Conceptual model of sensory, motivational, and central control determinants of pain. Output of T (transmission) cells of gate control system projects to sensory‐discriminative system and motivational‐affective system. Central control trigger is represented by line running from large‐fiber system to central control processes; these, in turn, project back to gate control system and to sensory‐discriminative and motivational‐affective systems. All 3 systems interact and project to motor system.

From Melzack


Figure 2.

Schematic illustration of different peptide systems in spinal cord of rat. At least 4 different types of neurons can be recognized. 1: Peptide neurons descend from brain, terminating in various parts of gray matter. Dotted lines, hypothetical projection. 2: Primary sensory neurons, with cell bodies in spinal ganglia, terminate in dorsal horn. 3: Local spinal interneurons or propriospinal neurons, with cell bodies in dorsal horn or in other parts of gray matter (not shown), terminate in dorsal horn. 4: Neurons in sympathetic lateral column (or in parasympathetic intermediolateral column) project out from spinal cord to periphery. Note that coexistence of peptides with classic transmitters, such as catecholamines and 5‐HT, is not indicated here. Abbreviations denote peptide against which antiserum was raised: ANG II, angiotensin II; APP, avian pancreatic polypeptide; CCK, cholecystokinin; ENK, enkephalin; NT, neurotensin; SOM, somatostatin; SP, substance P; TRH, thyrotropin‐releasing hormone; VIP, vasoactive intestinal polypeptide.

From Hökfelt et al.


Figure 3.

A: schematic indicating location of Rexed's laminae from segment L7 of cat spinal cord. B: course and destination of afferent fibers from dorsal root to dorsal horn. Afferent fibers: 1, muscle spindle afferent; 2, hair afferent; 3, touch corpuscle afferent; 4, Aδ‐afferent; 5, C afferent.

A adapted from Rexed ; B from Wall


Figure 4.

Spinothalamic tract cell in primate with wide‐dynamic‐range receptive field. Cell was located in lateral portion of neck of dorsal horn (A). Receptive field included area sensitive to low‐intensity mechanical stimuli (black area in B), surrounded by area requiring higher‐intensity stimuli (hatched area). Cell was excited by hair movement (C), pressure (D), and pinch (E). Pinch was most effective stimulus. Temperature changes from 35°C to 50°C (F) and from 20°C to 10°C (G) excited cell. Lower traces in F and G are records of temperature at thermode‐skin interface. Time scale applies to C‐G.

From Chung et al.


Figure 5.

Viscerosomatic convergence in spinothalamic neuron of monkey (T12 segment, lamina V). A: responses to squeezing skin of flank, distension of urinary bladder (60‐ml volume injected rapidly), and manual compression of exposed ipsilateral testicle. B: summation of responses to distension of bladder (80 cm H2O) and squeezing skin of flank. C: reversed sequence of B.

From Milne et al.


Figure 6.

Reciprocal sensory interaction. Scheme to illustrate possible interactions among dorsal horn and substantia gelatinosa neurons, leading to reciprocal interaction between afferent inputs from mechanoreceptors and nociceptors. SG, substantia gelatinosa neurons as classified by Cervero et al. ; 1, 2, 3, and Th, classes of dorsal horn neurons according to Cervero et al. .

From Iggo


Figure 7.

Summary diagram of terminal and perikaryal immunoreactivity of glutamate decarboxylase (GAD) and peptide‐containing interneurons. ENK, enkephalin; SUB P, substance P; SOM, somatostatin; APP, avian pancreatic polypeptide; NT, neurotensin; 5‐HT, 5‐hydroxytryptamine. Perikarya with proximal dendritic segments illustrated against background of stipple, which indicates distribution of intrinsic peptide or GAD + terminals.

From Hunt et al.


Figure 8.

Diagram of neural systems important in pain and pain modulation. Small‐diameter nociceptive afferents (S) and larger‐diameter nonnociceptive fibers (L) activate spinal mechanisms leading to generation of impulses ascending to higher centers. Neurons in ventrobasal thalamus [ventralis posterolateralis shown here (VPL)] receive input from fibers of dorsal column‐medial lemniscal system and from that portion of ventrolateral spinal cord forming spinothalamic tract. Projection of these neurons to somatosensory (som sens) cortex provides basis for discriminative aspects of somesthesis, possibly including pain. Other fibers ascending from ventrolateral spinal cord send projections into brain stem reticular formation (RF) and to medial thalamus. Ascending reticular formation fibers also project to medial thalamus and hypothalamus (hyp), where they may influence limbic forebrain mechanisms subserving motivational and affective components of pain. Both discriminative and motivational‐affective systems are modulated by descending pathways acting at thalamic, brain stem, and spinal levels.

Adapted from Casey


Figure 9.

Responses of high‐threshold somatosensory area I cortical neuron (monkey) to mechanical and thermal stimuli. A: receptive field location was confined to glabrous skin of hallux. B: location of recording site was identified to be in layer 4 at junction between areas 3b and 1. C: peristimulus time histogram of responses to graded series of mechanical stimuli. D: film records of action potentials before (upper trace) and during (lower trace) noxious heat pulse from 35°C to 50°C. E: peristimulus time histogram of response to noxious heat pulse (time course of temperature indicated above abscissa). Bin width was 1 s for all peristimulus time histograms.

From Kenshalo and Isensee


Figure 10.

Schematic illustration of sections through rostral medulla of rat and cat. Several structures are indicated, each of which probably exerts control of spinal nociceptors: NRM; nucleus reticularis gigantocellularis (Rgc); nucleus reticularis gigantocellularis pars α (Rgc α); nucleus reticularis magnocellularis (Rmc); probable rat analog, nucleus reticularis paragigantocellularis (Rpg); and more lateral nucleus reticularis paragigantocellularis lateralis (Rpgl). Serotonin‐containing neurons are found in NRM and in Rpgl but not in Rmc or Rpg.

From Basbaum and Fields


Figure 11.

Effect of intravenous morphine on wide‐dynamic‐range neuron in dorsal horn of rat. Poststimulus histogram [50 trials; time base (TB), 5 ms] of responses induced by stimulation of sural nerve (16 V; pulse duration, 1 ms). First component related to Aα‐input is truncated; only discharges related to Aδ‐ and C‐fiber inputs are considered. Length between nerve‐stimulating electrodes and recording site in cord was 18 cm.

From LeBars et al.


Figure 12.

Ratemeter recording of wide‐dynamic‐range neuron displaying depressant response to microiontophoretic application of Met‐enkephalin (M‐Enk). Depressant effect of M‐Enk on this spontaneously active neuron was antagonized by prior iontophoretic application of naloxone. Recordings are continuous, and drug applications are indicated by horizontal bars; ejection currents (subscripts) are given in nanoamperes (10−9 A).

Adapted from Zieglgänsberger and Tulloch


Figure 13.

Schematic diagram illustrating hypothesized (enkephalinergic) control mechanism of neurons in substantia gelatinosa over multimodal neurons involved in somatosensory perception. Small bipolar (enkephalinergic) neuron impinges together with afferent large‐ and small‐diameter fibers on dendrites of laminae 4 and 5 cells carrying opiate receptors (dots). Inhibitory interneurons (IN) have postulated to make C‐fiber input to bipolar neurons inhibitory (see ref. ). Descending pathways can act directly, e.g., via noradrenergic, dopaminergic, or serotonergic pathways, on neurons of spinothalamic system (L4 and L5) or via enkephalinergic neurons in substantia gelatinosa (only this part of descending influence would be sensitive to opiate antagonist naloxone). Presynaptic contact is marked with question mark. +, ‐ Represent excitatory and inhibitory influences. SOM indicates possibility of primary afferent inhibition by somatostatin. This inhibitory‐acting neuropeptide was demonstrated in primary afferent small‐caliber fibers (see ref. ).

Adapted from Zieglgänsberger and Tulloch


Figure 14.

Different types of descending inhibitory influences in dorsal horn. A: encoding of intensity of noxious skin heating in single dorsal horn neuron as affected by stimulation in periaqueductal gray (PAG) and mesencephalic lateral reticular formation (LRF). B: location of stimulation sites in midbrain.

From Carstens et al.


Figure 15.

Increased spontaneous firing and enhanced nociceptive responses of lamina V neuron after naloxone administration. Neuron was excited by alternately heating glabrous skin of left hindpaw above 45°C and deflecting adjacent hairs by a moving air jet. Responses remained enhanced for >20 min after administration of naloxone, 0.5 mg/kg iv.

From Duggan and Johnson


Figure 16.

Increased reflexes and excitatory postsynaptic potentials (EPSPs) recorded in motoneuron after administration of naloxone, 0.1 mg/kg iv. Reflexes were recorded in S1 ventral root. Intracellular records were obtained with 1.2 M potassium citrate‐containing electrode. A: responses to electrical stimulation combined medial and lateral gastrocnemius nerves (MLG) with stimulus strength 1.5 times threshold for fastest‐conducting fibers. On reflex records, arrow marks timing of nerve stimulus. On intracellular records, stimulus coincided with the trailing edge of 2‐mV calibration pulse. After naloxone, neuron fired to each nerve stimulus. Upward arrow indicates that upper part of each action potential was clipped by amplifier gain used to record the much smaller EPSP. B: responses to stimulation of tibial nerve with stimulus 3 times threshold for fastest‐conducting fibers. Timing of stimulus as outlined in A.

From Duggan


Figure 17.

Effects of diffuse noxious inhibitory control evoked from various parts of body by noxious pinch (period of pinch arrowed) on response of convergent neuron to regular light stroking (dots) applied every 10 s.

From LeBars et al.


Figure 18.

A: inhibition of responses of wide‐dynamic‐range spinothalamic tract cell of monkey to stimulation of A‐ or C‐fibers of sural nerve by descending volleys initiated by stimulation in nucleus raphe magnus (NRM). Histograms in A and C show control responses to stimulation of A‐ and C‐fibers, respectively. Inset in C is C‐fiber volley recorded from sural nerve. Stimulation in NRM during times shown by bars in B and D (150‐μA pulses at 333 Hz) inhibited responses. E shows location of stimulating electrode in sagittal section at midline of brain stem.

From Gerhart et al.


Figure 19.

Inhibition of high‐threshold spinothalamic tract (STT) cell of monkey by stimulation in NRM. A: response of cell to electrical stimulation of skin and inhibition of this response after stimulation in NRM (10 50‐μA shocks at 333 Hz). Inhibition (as percentage of control response) increases with increasing stimulus strength (10 stimuli) (B) or with increasing numbers of stimulus pulses (100 μA) (C). D: location of STT cell. E: receptive field. F: location of stimulation electrode. RM, nucleus raphe magnus; VII, facial nucleus. G: time course of inhibition (stimulus‐train duration indicated by solid bar at bottom).

From Willis et al.


Figure 20.

Inhibitory postsynaptic potential (IPSP) evoked in spinothalamic neuron by NRM stimulation. Antidromic spike in A resulted from stimulation in contralateral ventral posterior lateral nucleus of thalamus. For this record, calibration bars at center bottom represent 20 mV and 2 ms. Spikes in B are background discharge of impaled cell. Stimulation at point indicated in inset in C inhibited background discharge. Stimulus‐train parameters for this and remaining records were 100‐ms train of 0.1‐ms pulses at 333 Hz and 200 μA. Calibrations: 20 mV, 20 ms. The IPSP in D was recorded with DC‐coupled amplifier. Hyperpolarization outlasted sweep, as shown by comparison with reference trace. The NRM‐train duration indicated by horizontal bar under record in this and following traces. Calibrations: 2 mV, 50 ms. E‐H: IPSP during passage of graded amounts of current through acetate‐filled microelectrode. I: field potential evoked by same NRM stimulus when micro‐electrode was just outside cell. Calibrations: 2 mV, 20 ms.

From Giesler et al.


Figure 21.

Schematic representation of system employed for superfusing in situ spinal cord of anesthetized rat. Polyethylene 10 (PE 10) catheter used for infusion is inserted through cisterna magna to caudal level of lumbar cord. Outflow cannula is placed into cisterna magna. Artificial cerebrospinal fluid is perfused at rate of 100 μl/min and collected by withdrawal syringe and iced sampling tubes. Modification of release from spinal cord is achieved in this schematic by placement of electrode into raphe magnus. In other experiments, microinjection cannulae were placed into periaqueductal gray.

From Yaksh and Hammond


Figure 22.

Release of serotonin and norepinephrine into spinal cord superfusates of 2 representative rats after electrical stimulation of nucleus raphe magnus. Left: sites of stimulation indicated on coronal sections of medulla by black circles. After collection of 25‐min sample of superfusate to determine basal efflux of serotonin and norepinephrine, raphe magnus was stimulated at 25 Hz with 0.5 ms square‐wave pulses of either 150 or 250 μA for 25 min. During stimulation, another sample of superfusate was collected to determine release of serotonin and norepinephrine evoked by raphe stimulation. Quantitation of amines was by high‐pressure liquid chromatography with electrochemical detection. Right: release of serotonin (5‐HT) and norepinephrine (NE) expressed as ng/ml superfusate under basal conditions (B; open bars) and during stimulation of raphe magnus (S; stippled bars).

From Yaksh and Hammond
References
 1. Abols, I. A., and A. I. Basbaum. Afferent connections of the rostral medulla of the cat: a neural substrate for midbrainmedullary interactions in the modulation of pain. J. Comp. Neurol. 201: 285–297, 1981.
 2. Adams, J. E. Naloxone reversal of analgesia produced by brain stimulation in the human. Pain 2: 161–166, 1976.
 3. Adams, J. E., Y. Hosobuchi, and H. L. Fields. Stimulation of internal capsule for relief of chronic pain. J. Neurosurg. 41: 740–744, 1974.
 4. Adler, M., W. Kostowski, M. Recchia, and R. Samanin. Anatomical specificity as the critical determinant of the inter‐relationship between raphe lesions and morphine analgesia. Eur. J. Pharmacol. 32: 39–44, 1975.
 5. Ainsworth, A., P. Hall, P. D. Wall, G. Allt, M. MacKenzie, S. Gibson, and J. M. Polak. Effects of capsaicin applied locally to adult peripheral nerve. II. Anatomy and enzyme and peptide chemistry of peripheral nerve and spinal cord. Pain 11: 379–388, 1981.
 6. Akaike, A., T. Shibata, M. Satoh, and H. Takagi. Analgesia induced by microinjection of morphine into, and electrical stimulation of, the nucleus reticularis paragigantocellularis of rat medulla oblongata. Neuropharmacology 17: 775–778, 1978.
 7. Akerman, B., S. Rosell, and K. Folkers. Intrathecal (D‐Pro2, K‐Trp7,9)‐SP elicits hypoalgesia and motor blockade in the rat and antagonizes noxious responses induced by substance P. Acta Physiol. Scand. 114: 631–633, 1982.
 8. Akil, H., and J. C. Liebeskind. Monoaminergic mechanisms of stimulation‐produced analgesia. Brain Res. 94: 279–296, 1975.
 9. Akil, H., J. Madden, R. L. Patrick, and J. D. Barchas. Stress‐induced increase in endogenous opiate peptides: concurrent analgesia and its partial reversal by naloxone. In: Opiates and Endogenous Opioid Peptides, edited by H. W. Kosterlitz. Amsterdam: Elsevier/North‐Holland, 1976, p. 63–70.
 10. Akil, H., and D. J. Mayer. Antagonism of stimulation‐produced analgesia by p‐CPA, a serotonin synthesis inhibitor. Brain Res. 44: 692–697, 1972.
 11. Akil, H., D. J. Mayer, and J. C. Liebeskind. Antagonism of stimulation‐produced analgesia by naloxone, a narcotic antagonist. Science 191: 961–962, 1976.
 12. Akil, H., D. E. Richardson, and J. D. Barchas. Pain control by focal brain stimulation in man: relationship to enkephalins and endorphins. In: Mechanisms of Pain and Analgesic Compounds, edited by R. F. Beers and E. G. Basset. New York: Raven, 1979, p. 239–247. (Miles Int. Symp. 11.)
 13. Akil, H., D. E. Richardson, J. D. Barchas, and C. H. Li. Appearance of beta‐endorphine‐like immunoreactivity in human ventricular cerebrospinal fluid upon analgetic electrical stimulation. Proc. Natl. Acad. Sci. USA 75: 5170–5172, 1978.
 14. Akil, H., D. E. Richardson, J. Hughes, and J. D. Barchas. Enkephalin‐like material elevated in ventricular cerebrospinal fluid of pain patients after analgesic focal stimulation. Science 201: 463–465, 1978.
 15. Akil, H., S. J. Watson, E. Young, E. L. Lewis, H. Khachaturian, and J. M. Walker. Endogenous opioids: biology and function. Annu. Rev. Neurosci. 7: 223–225, 1984.
 16. Albe‐Fessard, D., and J. M. Besson. Convergent thalamic and cortical projections—the non‐specific system. In: Handbook of Sensory Physiology. Somatosensory System, edited by A. Iggo. Berlin: Springer‐Verlag, 1973, vol. II, p. 489–560.
 17. Albe‐Fessard, D., D. Levante, and Y. Lamour. Origin of spino‐thalamic tract in monkeys. Brain Res. 65: 503–509, 1974.
 18. Amir, S., and Z. Amit. Endogenous opioid ligands may mediate stress‐induced changes in the affective properties of pain related behaviour in rats. Life Sci. 23: 1143–1151, 1978.
 19. Amir, S., and Z. Amit. The pituitary gland mediates acute and chronic pain responsiveness in stressed and non‐stressed rats. Life Sci. 24: 439–448, 1979.
 20. Andersen, R. K., J. P. Lund, and E. Puil. The effects of iontophoretic applications of morphine and putative neurotransmitters on neurons of the trigeminal nuclei oralis and caudalis. In: Pain in the Trigeminal Region, edited by D. J. Anderson and B. Matthews. Amsterdam: Elsevier/North‐Holland, 1977, p. 271–284.
 21. Andersen, R. K., J. P. Lund, and E. Puil. Enkephalin and substance P effects related to trigeminal pain. Can. J. Physiol. Pharmacol. 56: 216–222, 1978.
 22. Anderson, S. D., A. I. Basbaum, and H. L. Fields. Response of medullary raphe neurons to peripheral stimulation and to systemic opiates. Brain Res. 123: 363–368, 1977.
 23. Angaut‐Petit, D. The dorsal column system. II. Functional properties and bulbar relay of the postsynaptic fibers of the cat's fasciculus gracilis. Exp. Brain Res. 22: 471–493, 1975.
 24. Aronin, N., M. DiFiglia, A. S. Liotta, and J. B. Martin. Ultrastructural localization and biochemical features of immunoreactive leu‐enkephalin in monkey dorsal horn. J. Neurosci. 1: 561–577, 1981.
 25. Aston‐Jones, G., M. Segal, and F. E. Bloom. Brain aminergic neurons exhibit marked variability in conduction velocity. Brain Res. 195: 215–222, 1980.
 26. Atweh, S. F., and M. J. Kuhar. Autoradiographic localization of opiate receptors in rat brain. I. Spinal cord and lower medulla. Brain Res. 124: 53–67, 1977.
 27. Atweh, S. F., and M. J. Kuhar. Autoradiographic localization of opiate receptors in rat brain. II. The brain stem. Brain Res. 129: 1–12, 1977.
 28. Azami, J., M. B. Llewelyn, and M. H. T. Roberts. The contribution of nucleus reticularis paragigantocellularis and nucleus raphe magnus to the analgesia produced by systemically administered morphine, investigated with the microinjection technique. Pain 12: 229–246, 1982.
 29. Bahr, R., H. Blumberg, and W. Jänig. Do dichotomizing afferent fibers exist which supply visceral organs as well as somatic structures? A contribution to the problem of referred pain. Neurosci. Lett. 24: 25–28, 1981.
 30. Baizman, E. R., B. M. Cox, O. H. Osman, and A. Goldstein. Experimental alterations of endorphin levels in rat pituitary. Neuroendocrinology 28: 402–414, 1979.
 31. Balagura, S., and T. Ralph. The analgesic effect of electrical stimulation of the diencephalon and mesencephalon. Brain Res. 60: 369–379, 1973.
 32. Barasi, S., and S. Pay. Influence of striatal and limbic afferents on nociceptive nigral neurons. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 169–177.
 33. Barbaresi, P., F. Conti, and T. Manzoni. Periaqueductal grey projection to the ventrobasal complex in the cat: a horse‐radish peroxidase study. Neurosci. Lett. 30: 205–209, 1982.
 34. Barber, J., and D. J. Mayer. Evaluation of the efficacy and neural mechanism of a hypnotic analgesia procedure in experimental and clinical dental pain. Pain 4: 41–48, 1977.
 35. Barber, R. P., J. E. Vaughn, K. Saito, B. J. McLaughlin, and E. Roberts. GABAergic terminals are presynaptic to primary afferent terminals in the substantia gelatinosa of the rat spinal cord. Brain Res. 141: 35–55, 1978.
 36. Barber, R. P., J. E. Vaughn, J. R. Slemmon, P. M. Salvaterra, E. Roberts, and S. E. Leeman. The origin, distribution and synaptic relationship of substance P axons in rat spinal cord. J. Comp. Neurol. 184: 331–352, 1979.
 37. Barker, J. L., D. L. Gruol, L. M. Huang, J. F. McDonald, and T. G. Smith, Jr. Peptides: pharmacological evidence for three forms of chemical excitability in cultured mouse spinal neurons. Neuropeptides 1: 63–82, 1980.
 38. Barker, J. L., T. G. Smith, Jr., and J. H. Neale. Multiple membrane actions of enkephalin revealed using cultured spinal neurons. Brain Res. 154: 153–158, 1978.
 39. Barnes, C. D., S. J. Fung, and W. C. Adams. Inhibitory effects of substantia nigra on impulse transmission from nociceptors. Pain 6: 207–215, 1979.
 40. Barton, C., A. I. Basbaum, and H. L. Fields. Dissociation of supraspinal and spinal actions of morphine. A quantitative evaluation. Brain Res. 188: 487–498, 1980.
 41. Basbaum, A. I. Conduction of the effects of noxious stimulation by short‐fiber multisynaptic systems of the spinal cord of the rat. Exp. Neurol. 40: 699–716, 1973.
 42. Basbaum, A. I. Anatomical substrates for the descending control of nociception. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 119–133.
 43. Basbaum, A. I., C. H. Clanton, and H. L. Fields. Three bulbospinal pathways from the rostral medulla of the cat: an autoradiographic study of pain modulating systems. J. Comp. Neurol. 178: 209–224, 1978.
 44. Basbaum, A. I., and H. L. Fields. Endogenous pain control mechanisms: review and hypothesis. Ann. Neurol. 4: 451–462, 1978.
 45. Basbaum, A. I., and H. L. Fields. The origin of descending pathways in the dorsolateral funiculus of the spinal cord of the cat and rat: further studies on the anatomy of pain modulation. J. Comp. Neurol. 187: 513–522, 1979.
 46. Basbaum, A. I., and H. L. Fields. Endogenous pain control systems: brainstem spinal pathways and endorphin circuitry. Annu. Rev. Neurosci. 7: 309–338, 1984.
 47. Basbaum, A. I., M. S. Moss, and E. I. Glazer. Opiate and stimulation‐produced analgesia: the contribution of the monoamines. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 323–339.
 48. Baumgarten, H. G., and L. Lachenmayer. 5,7‐Dihydroxytryptamine: improvement in chemical lesioning of indolamine neurons in the mammalian brain. Z. Zellforsch. Mikrosk. Anat. 135: 399–414, 1972.
 49. Beall, J. E., A. E. Applebaum, R. D. Foreman, and W. D. Willis. Spinal cord potentials evoked by cutaneous afferents in the monkey. J. Neurophysiol. 40: 199–211, 1977.
 50. Beall, J. E., R. F. Martin, A. E. Applebaum, and W. D. Willis. Inhibition of primate spinothalamic tract neurons by stimulation in the region of the nucleus raphe magnus. Brain Res. 114: 328–333, 1976.
 51. Beaumont, A., and J. Hughes. Biology of opioid peptides. Annu. Rev. Pharmacol. Toxicol. 19: 245–267, 1979.
 52. Beck, P. W., and H. O. Handwerker. Bradykinin and serotonin effects on various types of cutaneous nerve fibers. Pfluegers Arch. 347: 209–222, 1974.
 53. Beckstead, R. M., V. B. Domesick, and W. J. H. Nauta. Efferent connections of the substantia nigra and ventral tegmental area in the rat. Brain Res. 195: 161–217, 1979.
 54. Beecher, H. K. Measurement of subjective responses. In: Quantitative Effects of Drugs. New York: Oxford Univ. Press, 1959.
 55. Behbehani, M. M. The role of acetylcholine in the function of the nucleus raphe magnus in the interaction of this nucleus with the periaqueductal gray. Brain Res. 252: 299–307, 1982.
 56. Behbehani, M. M., and H. L. Fields. Evidence that an excitatory connection between the periaquaeductal gray and nucleus raphe magnus mediates stimulation produced analgesia. Brain Res. 170: 85–93, 1979.
 57. Behbehani, M. M., and A. Pert. A mechanism for the analgesic effect of neurotensin as revealed by behavioral and electrophysiological techniques. Brain Res. 324: 35–42, 1984.
 58. Behbehani, M. M., and S. L. Pomeroy. Effect of morphine injected in the periaquaeductal gray on the activity of single units in nucleus raphe magnus of the rat. Brain Res. 149: 266–269, 1978.
 59. Beitz, A. J. The sites of origin of brainstem neurotensin and serotonin projections to the rodent nucleus raphe magnus. Neuroscience 2: 829–834, 1982.
 60. Beitz, A. J. The organisation of afferent projections to the midbrain periaqueductal gray of the rat. Neuroscience 7: 133–159, 1982.
 61. Beitz, A. J. The nuclei of origin of brain stem enkephalin and substance P projections to the rodent nucleus raphe magnus. Neuroscience 7: 2753–2768, 1982.
 62. Belcher, G., and R. W. Ryall. Differential excitatory and inhibitory effects of opiates on non‐nociceptive and nociceptive neurones in the spinal cord of the rat. Brain Res. 145: 303–314, 1978.
 63. Belcher, G., R. W. Ryall, and R. Schaffner. The differential effects of 5‐hydroxytryptamine, noradrenaline and raphe stimulation on nociceptive and non‐nociceptive dorsal horn interneurones in the cat. Brain Res. 151: 307–321, 1978.
 64. Bell, J. A., and W. R. Martin. The effect of the narcotic antagonists naloxone, naltrexone and nalorphine on spinal cord C‐fiber reflexes evoked by electrical stimulation or radiant heat. Eur. J. Pharmacol. 42: 147–154, 1977.
 65. Bennett, G. J., M. Abdelmoumene, H. Hayashi, and R. Dubner. Physiology and morphology of substantia gelatinosa neurons intracellularly stained with horseradish peroxidase. J. Comp. Neurol. 194: 809–827, 1980.
 66. Bennett, G. J., M. Abdelmoumene, H. Hayashi, M. J. Hoffert, and R. Dubner. Spinal cord layer I neurons with axon collaterals that generate local arbors. Brain Res. 209: 421–426, 1981.
 67. Bennett, G. J., and D. J. Mayer. Inhibition of spinal cord interneurons by narcotic microinjection and focal electrical stimulation in the periaquaeductal gray matter. Brain Res. 172: 243–258, 1979.
 68. Bennett, G. J., M. A. Ruda, S. Gobel, and R. Dubner. Enkephalin immunoreactive stalked cells and lamina IIb islet cells in cat substantia gelatinosa. Brain Res. 240: 162–166, 1982.
 69. Benoist, J. M., V. Kayser, M. Gautron, and G. Guilbaud. Low dose of morphine strongly depresses responses of specific nociceptive neurons in the ventrobasal complex of the rat. Pain 15: 333–343, 1983.
 70. Berkowitz, B. A., and S. Sherman. Characterization of vasopressin analgesia. J. Pharmacol. Exp. Ther. 220: 329–339, 1982.
 71. Berntson, G. G., and B. S. Berson. Antinociceptive effects of intraventricular or systemic administration of vasopressin in the rat. Life Sci. 26: 455–459, 1980.
 72. Berntson, G. G., and J. M. Walker. Effect of opiate receptor blockade on pain sensitivity in the rat. Brain Res. Bull. 2: 157–159, 1977.
 73. Besson, J. M., G. Guilbaud, and D. Le Bars. Descending inhibitory influences exerted by the brain stem upon the activities of dorsal horn lamina V cells induced by intraarterial injection of bradykinin into the limb. J. Physiol. London 248: 725–739, 1975.
 74. Besson, J. M., J. L. Oliveras, A. Chaouch, and J. P. Rivot. Role of the raphe nuclei in stimulation producing analgesia. Adv. Exp. Med. Biol. 133: 153–176, 1981.
 75. Bhattacharya, S. K., P. R. Keshary, and A. K. Sanyal. Immobilization stress‐induced antinociception in rats: possible role of serotonin and prostaglandins. Eur. J. Pharmacol. 50: 83–85, 1978.
 76. Bird, S. J., and M. J. Kuhar. Iontophoretic application of opiates to the locus coeruleus. Brain Res. 122: 523–533, 1977.
 77. Bischoff, A. Congenital insensitivity to pain with anhidrosis. A morphometric study of sural nerve and cutaneous receptors in the human prepuce. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress on Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 53–65.
 78. Biscoe, T. J., A. W. Duggan, and D. Lodge. Effect of etorphine, morphine and diprenorphine on neurones of the cerebral cortex and spinal cord of the rat. Br. J. Pharmacol. 46: 201–212, 1972.
 79. Björklund, A., and G. Skagerberg. Simultaneous use of retrograde fluorescent tracers and fluorescence histochemistry for convenient and precise mapping of monoaminergic projections and collateral arrangements in the CNS. J. Neurosci. Methods 1: 261–277, 1979.
 80. Black, P., S. N. Cianci, and R. S. Markowitz. Alleviation of pain by hypothalamic stimulation in the monkey. Confin. Neurol. 34: 374–381, 1972.
 81. Bläsig, J., K. Reinhold, and A. Herz. Effect of 6‐hydroxy‐dopamine, 5,6‐dihydroxytryptamine and raphe lesions on the antinociceptive actions of morphine in rats. Psychopharmacologia 31: 111–119, 1973.
 82. Blessing, W. W., and J. P. Chalmers. Direct projection of catecholamine (presumably dopamine)‐containing neurons from hypothalamus to spinal cord. Neurosci. Lett. 11: 35–40, 1979.
 83. Bloom, F. E. Central noradrenergic systems: physiology and pharmacology. In: Psychopharmacology: A Generation of Progress, edited by M. A. Lipton, A. DiMascio, and K. F. Killam. New York: Raven, 1978, p. 131–141.
 84. Bloom, F. E. The endorphins: a growing family of pharmacologically pertinent peptides. Annu. Rev. Pharmacol. Toxicol. 23: 151–170, 1983.
 85. Bloom, F., E. Battenberg, J. Rossier, N. Ling, and R. Guillemin. Neurons containing beta‐endorphin in rat brain exist separately from those containing enkephalin: immuno‐cytochemical studies. Proc. Natl. Acad. Sci. USA 75: 1591–1595, 1978.
 86. Bodnar, R. J., M. Glusman, M. Brutus, A. Spiaggia, and D. D. Kelly. Analgesia induced by cold water stress: attenuation following hypophysectomy. Physiol. Behav. 23: 53–62, 1979.
 87. Bodnar, R. J., D. D. Kelly, M. Brutus, and M. Glusman. Stress‐induced analgesia: neural and hormonal determinants. Neurosci. Biobehav. Rev. 41: 87–100, 1979.
 88. Bodnar, R. J., D. D. Kelly, and M. Glusman. Stress‐induced analgesia: time course of pain reflex alterations following cold water swim. Bull. Psychon. Soc. 11: 333–336, 1978.
 89. Bodnar, R. J., D. D. Kelly, A. Mansour, and M. Glusman. Differential effects of hypophysectomy upon analgesia induced by two glucoprivic stressors and morphine. Pharmacol. Biochem. Behav. 11: 303–308, 1979.
 90. Bodnar, R. J., D. D. Kelly, A. Spiaggia, C. Ehrenberg, and M. Glusman. Dose‐dependent reductions by naloxone of analgesia induced cold water stress. Pharmacol. Biochem. Behav. 8: 667–672, 1978.
 91. Boethius, J., U. Lindblom, B. A. Meyerson, and L. Widen. Effects of multifocal brain stimulation on pain and somatosensory functions. In: Sensory Functions of the Skin in Primates, With Special Reference to Man, edited by Y. Zottermann. New York: Pergamon, 1976, p. 531–546.
 92. Bolles, R. C., and M. S. Fanselow. Endorphins and behavior. Annu. Rev. Psychol. 33: 87–101, 1982.
 93. Botticelli, L. J., B. M. Cox, and A. Goldstein. Immuno‐reactive dynorphin in mammalian spinal cord and dorsal root ganglia. Proc. Natl. Acad. Sci. USA 78: 7783–7786, 1981.
 94. Boureau, F., J. C. Willer, and S. Klinerock. Study of naloxone in normal awake man: effects on spinal reflexes. Neuropharmacology 17: 565–568, 1978.
 95. Bourgoin, S., J. L. Oliveras, J. Bruxelle, M. Hamon, and J. M. Besson. Electrical stimulation of the nucleus raphe magnus in the rat. Effect of 5‐HT metabolism in the spinal cord. Brain Res. 194: 377–389, 1980.
 96. Bowery, N. G., D. R. Hill, and A. L. Hudson. Characteristics of GABAB receptor binding sites on rat whole brain synaptic membranes. Br. J. Pharmacol. 78: 191–206, 1983.
 97. Bowery, N. G., D. R. Hill, A. L. Hudson, A. Doble, D. N. Middlemiss, J. S. Shaw, and M. J. Turnbull. (‐)Baclofen decreases neurotransmitter release in the mammalian CNS by an action at a novel GABA receptor. Nature London 283: 92–94, 1980.
 98. Bowery, N. G., G. W. Price, A. L. Hudson, D. R. Hill, D. P. Wilkin, and M. J. Turnbull. GABA receptor multiplicity. Visualization of different receptor types in the mammalian CNS. Neuropharmacology 23: 219–231, 1984.
 99. Bowker, R. M., H. W. M. Steinbusch, and J. D. Coulter. Serotoninergic and peptidergic projections to the spinal cord demonstrated by a combined retrograde HRP histochemical and immunocytochemical staining method. Brain Res. 211: 412–417, 1981.
 100. Bowker, R. M., K. N. Westlund, and J. D. Coulter. Origins of serotonergic projections to the spinal cord in rat: an immunocytochemical‐retrograde transport study. Brain Res. 226: 181–199, 1981.
 101. Bowsher, D. Diencephalic projections from the midbrain reticular formation. Brain Res. 95: 211–220, 1975.
 102. Bowsher, D. Role of the reticular formation in response to noxious stimulation. Pain 2: 361–378, 1976.
 103. Bradley, P. B., I. Briggs, R. J. Gayton, and L. A. Lambert. Effects of microiontophoretically applied methionine‐enkephalin on single neurones in rat brainstem. Nature London 261: 425–426, 1976.
 104. Braestrup, C., and M. Nielsen. Biochemical studies of CNS receptors. In: Handbook of Psychopharmacology. Biochemical Studies of CNS Receptors, edited by L. L. Iversen and S. H. Snyder. New York: Plenum, 1983, vol. 17, p. 285–384.
 105. Braga, P., S. Ferri, A. Santagostino, V. R. Olgiati, and A. Pecile. Lack of opiate receptor involvement in centrally induced calcitonin analgesia. Life Sci. 22: 971–978, 1978.
 106. Bramwell, G. J., and P. B. Bradley. Actions and interactions of narcotic agonists and antagonists on brainstem neurones. Brain Res. 73: 167–170, 1974.
 107. Breazile, J. E., and R. L. Kitchell. A study of fiber systems within the spinal cord of the domestic pig that subserve pain. J. Comp. Neurol. 133: 373–382, 1968.
 108. Brinkhus, H. B., E. Carstens, and M. Zimmermann. Encoding of graded noxious skin heating by neurons in posterior thalamus and adjacent areas in the cat. Neurosci. Lett. 15: 37–42, 1979.
 109. Brodie, M. S., and H. R. Proudfit. The induction of analgesia by local injection of carbachol into the nucleus raphe magnus (Abstract). Neuroscience 8: 770, 1982.
 110. Brown, A. G. Organization in the spinal cord. In: The Anatomy and Physiology of Identified Neurones, Berlin: Springer‐Verlag, 1981.
 111. Brown, A. G., P. B. Brown, R. E. W. Fyffe, and L. M. Pubols. Receptive field organisation and response properties of spinal neurones with axons ascending the dorsal columns in the cat. J. Physiol. London 337: 575–588, 1983.
 112. Brune, K., and K. D. Rainsford. New trends in the understanding and development of anti‐inflammatory drugs. Trends Pharmacol. Sci. 1: 95–97, 1979.
 113. Buchsbaum, M. S., G. C. Davis, and W. E. Bunney, Jr. Naloxone alters pain perception and somatosensory evoked potentials in normal subjects. Nature London 270: 620–622, 1977.
 114. Buckett, W. R. Peripheral stimulation in mice induces short‐duration analgesia preventable by naloxone. Eur. J. Pharmacol. 58: 169–178, 1979.
 115. Buijs, R. M., D. F. Swaab, J. Dogterom, and F. W. von Leeuwen. Intra‐ and extrahypothalamic vasopressin and oxytocin pathways in the rat. Cell Tissue Res. 186: 423–433, 1978.
 116. Burton, H., and E. G. Jones. The posterior thalamic region and its cortical projection in new world and old world monkeys. J. Comp. Neurol. 168: 249–302, 1976.
 117. Burton, H., and A. D. Loewy. Descending projections from the marginal cell layer and other regions of monkey spinal cord. Brain Res. 116: 485–491, 1976.
 118. Burton, H., and A. D. Loewy. Projections to the spinal cord from medullary somatosensory relay nuclei. J. Comp. Neurol. 173: 733–792, 1977.
 119. Cadden, S. W., L. Villanueva, D. Chitour, and D. Le Bars. Depression of activities of dorsal horn convergent neurones by propiospinal mechanisms triggered by noxious inputs: comparison with diffuse noxious inhibitory controls (DNIC). Brain Res. 275: 1–11, 1983.
 120. Campbell, J. N., and R. H. La Motte. Latency to detection of first pain. Brain Res. 266: 203–208, 1983.
 121. Carmody, J. J., P. R. Carroll, and D. Morgans. Naloxone increases pain perception in rats and mice. Life Sci. 24: 1149–1152, 1979.
 122. Carpenter, S., and B. Lynn. Vascular and sensory responses of human skin to mild injury after topical treatment with capsaicin. Br. J. Pharmacol. 73: 755–758, 1981.
 123. Carstens, E., H. Bihl, D. R. F. Irvine, and M. Zimmermann. Descending inhibition from medial and lateral midbrain of spinal dorsal horn neuronal responses to noxious and nonnoxious cutaneous stimuli in the cat. J. Neurophysiol. 45: 1029–1042, 1981.
 124. Carstens, E., M. Fraunhoffer, and S. N. Suberg. Inhibition of spinal dorsal horn neuronal responses to noxious skin heating by lateral hypothalamic stimulation in the cat. J. Neurophysiol. 50: 192–204, 1983.
 125. Carstens, E., M. Fraunhoffer, and M. Zimmermann. Serotonergic mediation of descending inhibition from midbrain periaqueductal gray, but not reticular formation, or spinal nociceptive transmission in the cat. Pain 10: 149–167, 1981.
 126. Carstens, E., D. Klumpp, and M. Zimmermann. The opiate antagonist, naloxone, does not affect descending inhibition from midbrain of nociceptive spinal neuronal discharges in the cat. Neurosci. Lett. 11: 323–327, 1979.
 127. Carstens, E., D. Klumpp, and M. Zimmermann. Differential inhibitory effects of medial and lateral midbrain stimulation on spinal neuronal discharges to noxious skin heating in the cat. J. Neurophysiol. 43: 332–342, 1980.
 128. Carstens, E., D. Klumpp, and M. Zimmermann. Time course and effective sites for inhibition from midbrain periaqueductal gray of spinal dorsal horn neuronal responses to cutaneous stimuli in the cat. Exp. Brain Res. 38: 425–430, 1980.
 129. Carstens, E., J. D. MacKinnon, and M. J. Guinan. Inhibition of spinal dorsal horn neuronal responses to noxious skin heating by medial preoptic and septal stimulation in the cat. J. Neurophysiol. 48: 981–991, 1982.
 130. Carstens, E., and D. L. Trevino. Laminar origins of spinothalamic projections in the cat as determined by retrograde transport of horseradish peroxidase. J. Comp. Neurol. 182: 151–166, 1978.
 131. Carstens, E., I. Tulloch, W. Zieglgänsberger, and M. Zimmermann. Presynaptic excitability induced by morphine in single cutaneous afferent C‐ and A‐fibers. Pfluegers Arch. 379: 143–147, 1979.
 132. Carstens, E., T. Yokota, and M. Zimmermann. Inhibition of spinal neuronal responses to noxious skin heating by stimulation of mesencephalic periaqueductal gray in the cat. J. Neurophysiol. 42: 558–568, 1979.
 133. Casey, K. L. Unit analysis of nociceptive mechanisms in the thalamus of the awake squirrel monkey. J. Neurophysiol. 29: 727–750, 1966.
 134. Casey, K. L. Escape elicited by bulboreticular stimulation in the cat. Int. J. Neurosci. 2: 29–34, 1971.
 135. Casey, K. L. Problems of defining pain. In: Neurosciences Research Program Bulletin, edited by F. W. L. Kerr and K. L. Casey. Cambridge, MA: MIT Press, 1978, p. 9–13.
 136. Casey, K. L. Reticular formation and pain: toward a unifying concept. In: Pain, edited by J. J. Bonica. New York: Raven, 1980, p. 93–105.
 137. Casey, K. L. Supraspinal mechanisms in pain: the reticular formation. In: Pain and Society, edited by H. W. Kosterlitz and L. Y. Terenius. Weinheim, West Germany: Chemie, 1980, p. 183–200. (Dahlem Konferenzen.)
 138. Casey, K. L., and E. G. Jones. Supraspinal mechanisms: a review of ascending pathways. Brain stem and thalamus. In: Neurosciences Research Program Bulletin, edited by F. W. L. Kerr and K. L. Casey. Cambridge, MA: MIT Press, 1978, p. 103–118.
 139. Casey, K. L., and T. J. Morrow. Ventral posterior thalamic neurons differentially responsive to noxious stimulation of the awake monkey. Science 221: 675–677, 1983.
 140. Castiglioni, A. J., M. C. Gallaway, and J. D. Coulter. Spinal projections from the midbrain in monkey. J. Comp. Neurol. 178: 329–346, 1978.
 141. Cervero, F. Somatic and visceral inputs to the thoracic spinal cord of the cat: effects of noxious stimulation of the biliary system. J. Physiol. London 337: 51–67, 1983.
 142. Cervero, F., and A. Iggo. The substantia gelatinosa of the spinal cord. A critical review. Brain 102: 717–772, 1980.
 143. Cervero, F., A. Iggo, and V. Molony. Responses of spino‐cervical tract neurones to noxious stimulation of the skin. J. Physiol. London 267: 537–558, 1977.
 144. Cervero, F., A. Iggo, and V. Molony. An electrophysiological study of neurones in the substantia gelatinosa Rolandi of the cat's spinal cord. Q. J. Exp. Physiol. 64: 297–314, 1979.
 145. Cervero, F., A. Iggo, and H. Ogawa. Nociceptor‐driven dorsal horn neurones in the lumbar spinal cord of the cat. Pain 2: 5–24, 1976.
 146. Cervero, F., and H. A. McRitchie. Neonatal capsaicin does not affect unmyelinated efferent fibers of autonomic nervous system: functional evidence. Brain Res. 239: 283–288, 1982.
 147. Cervero, F., V. Molony, and A. Iggo. Extracellular and intracellular recordings from neurones in the substantia gelatinosa. Brain Res. 136: 565–569, 1977.
 148. Chance, W. T. Autoanalgesia: opiate and non‐opiate mechanisms. Neurosci. Biobehav. Rev. 4: 55–67, 1980.
 149. Chance, W. T., and J. A. Rosecrans. Lack of cross‐tolerance between morphine and autoanalgesia. Pharmacol. Biochem. Behav. 11: 639–642, 1979.
 150. Chance, W. T., and J. A. Rosecrans. Lack of effect of naloxone on autoanalgesia. Pharmacol. Biochem. Behav. 11: 643–646, 1979.
 151. Chance, W. T., A. C. White, G. M. Krynock, and J. A. Rosecrans. Conditional fear‐induced antinociception and decreased binding of [3H]N‐leu‐enkephalin to rat brain. Brain Res. 141: 371–374, 1978.
 152. Chang, H. T. Acupuncture analgesia today. Chin. Med. J. 92: 7–16, 1979.
 153. Chan‐Palay, V., G. Jonsson, and S. L. Palay. Serotonin and substance P coexist in neurons of the rat's central nervous system. Proc. Natl. Acad. Sci. USA 75: 1582–1586, 1978.
 154. Chan‐Palay, V., and S. L. Palay. Immunocytochemical identification of substance P cells and their processes in rat sensory ganglia and their terminals in the spinal cord: light microscopic studies. Proc. Natl. Acad. Sci. USA 74: 3597–3601, 1977.
 155. Chan‐Palay, V., and S. L. Palay. Ultrastructural identification of substance P cells and their processes in rat sensory ganglia and their terminals in the spinal cord by immunocytochemistry. Proc. Natl. Acad. Sci. USA 74: 4050–4054, 1977.
 156. Chan‐Palay, V., and S. L. Palay. Coexistence of Neuroactive Substances in Neurons. New York: Wiley, 1984.
 157. Chapman, C. R. Signal detection theory and pain. Anaesthesiology 44: 358–359, 1976.
 158. Chapman, C. R., and C. Benedetti. Analgesia following transcutaneous electrical stimulation and its partial reversal by a narcotic antagonist. Life Sci. 21: 1645–1648, 1977.
 159. Chapman, C. R., C. Benedetti, Y. Colpitts, and R. Gerlach. Naloxone fails to reverse pain thresholds elevated by acupuncture: acupuncture analgesia reconsidered. Pain 16: 13–31, 1983.
 160. Chapman, C. R., A. C. Chen, and J. J. Bonica. Effects of intrasegmental electrical acupuncture on dental pain: evaluation by threshold estimation and sensory decision theory. Pain 3: 213–227, 1977.
 161. Chapman, C. R., Y. M. Colpits, C. Benedetti, R. Kitaeff, and J. D. Gehrig. Evoked potential assessment of acupunctural analgesia: attempted reversal with naloxone. Pain 9: 183–197, 1980.
 162. Chapman, C. R., J. D. Gehrig, and M. E. Wilson. Acupuncture, pain, and signal detection theory. Science 189: 65, 1975.
 163. Chavkin, C., I. F. James, A. Goldstein. Dynorphin is a specific endogenous ligand of the kappa opioid receptor. Science 215: 413–415, 1982.
 164. Cheng, R. S. S., and B. Pomeranz. Electroacupuncture analgesia could be mediated by at least two pain‐relieving mechanisms; endorphin and non‐endorphin systems. Life Sci. 25: 1957–1962, 1979.
 165. Cheng, R. S. S., and B. Pomeranz. A combined treatment with D‐amino acids and electroacupuncture produces a greater analgesia then either treatment alone: naloxone reverses these effects. Pain 8: 231–236, 1980.
 166. Chesher, G. B., and B. Chan. Footshock‐induced analgesia in mice: its reversal by naloxone and cross‐tolerance with morphine. Life Sci. 21: 1569–1574, 1977.
 167. Chiang, C. Y., H. C. Tu, Y. F. Chao, Y. H. Pai, H. K. Ku, J. K. Cheng, H. Y. Shan, and F. E. Yang. Effect of electrolytic lesions or intracerebral injections of 5,6‐dihydroxytryptamine in raphe nuclei on acupuncture analgesia in rats. Chin. Med. J. 92: 129–136, 1979.
 168. Chiodo, L. A., and B. S. Bunney. Proglumide: selective antagonism of excitatory effects of cholecystokinin in central nervous system. Science 219: 1449–1451, 1983.
 169. Chipkin, R. E., M. B. Latranyi, and L. C. Iorio. Potentiation of stress‐induced analgesia (SIA) by thiorphan and its block by naloxone. Life Sci. 31: 1189–1192, 1982.
 170. Chitour, D., A. H. Dickenson, and D. Le Bars. Pharmacological evidence for the involvement of serotoninergic mechanisms in diffuse noxious inhibitory controls (DNIC). Brain Res. 236: 329–337, 1982.
 171. Christensen, B. N., and E. R. Perl. Spinal neurons specifically excited by noxious or thermal stimuli: marginal zone of the dorsal horn. J. Neurophysiol. 33: 293–307, 1970.
 172. Chu, N., and F. E. Bloom. The catecholamine containing neurons in the cat dorsolateral pontine tegmentum: distribution of the cell bodies and some axonal projections. Brain Res. 66: 1–21, 1974.
 173. Chung, J. M., Z. R. Fang, C. L. Cargill, and W. D. Willis. Prolonged, naloxone‐reversible inhibition of the flexion reflex in the cat. Pain 15: 35–53, 1983.
 174. Chung, J. M., Z. R. Fang, Y. Hori, K. H. Lee, and W. D. Willis. Prolonged inhibition of primate spinothalamic tract cells by peripheral nerve stimulation. Pain 19: 259–275, 1984.
 175. Chung, J. M., D. R. Kenshalo, Jr., K. D. Gerhart, and W. D. Willis. Excitation of primate spinothalamic neurons by cutaneous C‐fiber volleys. J. Neurophysiol. 42: 1354–1369, 1979.
 176. Chung, J. M., G. A. Kevetter, R. P. Yezierskik, L. H. Haber, R. F. Martin, and W. D. Willis. Midbrain nuclei projecting to the medial medulla oblongata in the monkey. J. Comp. Neurol. 214: 93–102, 1983.
 177. Chung, J. M., K. H. Lee, K. Endo, and R. E. Coggeshall. Activation of central neurons by ventral root afferents. Science 222: 934–935, 1983.
 178. Chung, K., and R. E. Coggeshall. Primary afferent axons in the tract of Lissauer in the cat. J. Comp. Neurol. 186: 451–464, 1979.
 179. Clark, S. L., and R. W. Ryall. The antinociceptive action of etorphine in the dorsal horn is due to a direct spinal action and not to activation of descending inhibition. Br. J. Pharmacol. 78: 307–319, 1983.
 180. Clark, W. C. Measurement of pain in humans. Signal detection theory and pain. In: Neurosciences Research Program Bulletin, edited by F. W. L. Kerr and K. L. Casey. Cambridge, MA: MIT Press, 1978, p. 14–27.
 181. Clark, W. C., and J. C. Yang. Acupunctural analgesia? Evaluation by signal detection theory. Science 184: 1096–1098, 1974.
 182. Clineschmidt, B. V., and J. C. McGuffin. Neurotensin administered intracisternally inhibits responsiveness of mice to noxious stimuli. Eur. J. Pharmacol. 46: 395–396, 1977.
 183. Clineschmidt, B. V., J. C. McGuffin, and P. B. Bunting. Neurotensin: antinocisponsive action in rodents. Eur. J. Pharmacol. 54: 129–139, 1979.
 184. Coggeshall, R. E., J. D. Coulter, and W. D. Willis. Unmyelinated axons in the ventral roots of the cat lumbosacral enlargement. J. Comp. Neurol. 153: 39–58, 1974.
 185. Coggeshall, R. E., K. A. P. Hong, L. A. Langford, H. G. Schaible, and R. F. Schmidt. Discharge characteristics of fine medial articular afferents at rest and during passive movements of inflamed knee joints. Brain Res. 272: 185–188, 1983.
 186. Coimbra, A., B. P. Sodre‐Borges, and M. M. Magalhaes. The substantia gelatinosa Rolandi of the rat. Fine structure, cytochemistry (acid phosphatase) and changes after dorsal root section. J. Neurocytol. 3: 199–217, 1974.
 187. Commissiong, J. W., C. L. Galli, and N. H. Neff. Differentiation of dopaminergic and noradrenergic neurons in rat spinal cord. J. Neurochem. 30: 1095–1099, 1978.
 188. Commissiong, J. W., S. Gentleman, and N. H. Neff. Spinal cord dopaminergic neurones: evidence for an uncrossed nigrospinal pathway. Neuropharmacology 18: 565–568, 1979.
 189. Corbett, A. D., S. J. Patterson, A. T. McKnight, J. Magnan, and H. W. Kosterlitz. Dynorphin (1–8) and dynorphin (1–9) are ligands for the kappa subtype of opiate receptor. Nature London 299: 79–81, 1982.
 190. Coulter, J. D., R. A. Maunz, and W. D. Willis. Effects of stimulation of sensorimotor cortex on primate spinothalamic neurons. Brain Res. 65: 351–356, 1974.
 191. Craig, A. D., Jr., and H. Burton. Spinal and medullary lamina I projection to nucleus submedius in medial thalamus: a possible pain center. J. Neurophysiol. 45: 443–466, 1981.
 192. Craig, A. D., Jr., S. J. Wiegand, and J. L. Price. The thalamocortical projection of the nucleus submedius in the cat. J. Comp. Neurol. 206: 28–48, 1982.
 193. Crowley, W. R., R. Jacobs, J. Volpe, J. F. Rodriguez‐Sierra, and B. R. Komisaruk. Analgesic effect of vaginal stimulation in rats: modulation by graded stimulus intensity and hormones. Physiol. Behav. 16: 483–488, 1976.
 194. Crowley, W. R., J. F. Rodriguez‐Sierra, and B. R. Komisaruk. Analgesia induced by vaginal stimulation in rats is apparently independent of a morphine‐sensitive process. Psychopharmacology 54: 223–225, 1977.
 195. Crowley, W. R., J. F. Rodriguez‐Sierra, and B. R. Komisaruk. Monoaminergic mediation of the antinociceptive effect of vaginal stimulation. Brain Res. 137: 67–84, 1977.
 196. Croze, S., C. Antonietti, and R. Duclaux. Changes in burning pain threshold induced by acupuncture in man. Brain Res. 104: 335–340, 1976.
 197. Cuello, A. C., J. V. Priestley, and M. R. Matthews. Localisation of substance P in neuronal pathways. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 55–83. (Ciba Found. Symp. 91.)
 198. Curtis, D. R., C. J. A. Game, G. A. R. Johnston, and R. M. McCulloch. Central effects beta‐(p‐chlorophenol)‐gamma‐aminobutyric acid. Brain Res. 70: 493–499, 1974.
 199. Cutting, D. A., and C. C. Jordan. Alternative approaches to analgesia: baclofen as a model compound. Br. J. Pharmacol. 54: 171–179, 1975.
 200. Dahlström, A., and K. Fuxe. Evidence for the existence of monamine containing neurons in the central nervous system. I. Demonstration of monoamines in the cell bodies of brain stem neurons. Acta Physiol. Scand. Suppl. 232: 1–55, 1964.
 201. Dahlström, A., and K. Fuxe. Evidence for the existence of monoamine containing neurons in the central nervous system. II. Experimentally induced changes in the intraneuronal amine levels of bulbospinal neuron systems. Acta Physiol. Scand. Suppl. 247: 1–36, 1965.
 202. D'Amour, F. E., and D. L. Smith. A method for determining loss of pain sensation. J. Pharmacol. Exp. Ther. 72: 74–79, 1941.
 203. Davidoff, R. A., and E. S. Sears. The effects of Lioresal on synaptic activity in the isolated spinal cord. Neurology 24: 957–963, 1974.
 204. Davies, J. Selective depression of synaptic excitation in cat spinal neurones by baclofen: an iontophoretic study. Br. J. Pharmacol. 72: 373–384, 1981.
 205. Davies, J., and S. E. Johnstone. Selective antinociceptive effects of tizanidine (DS 103–282), a centrally acting muscle relaxant, on dorsal horn neurones in the feline spinal cord. Br. J. Pharmacol. 82: 409–421, 1984.
 206. Davies, J. E., and M. H. T. Roberts. 5‐Hydroxytryptamine reduces substance P responses on dorsal horn interneurones: a possible interaction of neurotransmitters. Brain Res. 217: 399–404, 1981.
 207. Davis, G. C., M. S. Buchsbaum, and W. E. Bunney. Naloxone decreases diurnal variation in pain sensitivity and somatosensory evoked potentials. Life Sci. 23: 1449–1460, 1978.
 208. Deakin, J. F. W., A. H. Dickenson, and J. O. Dostrovsky. Morphine effects on raphe magnus neurones. J. Physiol. London 267: 43–45, 1977.
 209. De Castro Costa, M., P. De Sutter, J. Gybels, and J. Van Hees. Adjuvant‐induced arthritis in rats: a possible animal model of chronic pain. Pain 10: 173–185, 1981.
 210. De Feudis, F. V. GABAergic analgesia: implications for GABAergic therapy for drug addictions. Drug Alcohol Depend. 14: 101–111, 1984.
 211. De Lanerolle, N. C., and C. C. La Motte. Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. I. Substance P immunoreactivity. Brain Res. 274: 31–49, 1983.
 212. Demenge, P., C. Feuerstein, P. Mouchet, and B. Guerin. Stereospecific binding of 3H‐haloperidol in rat dorsal spinal cord. Eur. J. Pharmacol. 66: 117–120, 1980.
 213. Demenge, P., P. Mouchet, B. Guerin, and C. Feuerstein. Identification and distribution of neuroleptic binding sites in the rat spinal cord. J. Neurochem. 37: 53–59, 1981.
 214. Dickenson, A. H. The inhibitory effects of thalamic stimulation on the spinal transmission of nociceptive information in the rat. Pain 17: 213–224, 1983.
 215. Dickenson, A. H., and D. Le Bars. Diffuse noxious inhibitory control (DNC) involve trigeminothalamic and spinothalamic neurones in the rat. Exp. Brain Res. 49: 174–180, 1983.
 216. Dickenson, A. H., J. L. Oliveras, and J. M. Besson. Role of the nucleus raphe magnus in opiate analgesia as studied by the microinjection technique in the rat. Brain Res. 170: 95–111, 1979.
 217. DiFiglia, M., N. Aronin, and S. E. Leeman. Light microscopic and ultrastructural localization of immunoreactive substance P in the dorsal horn of monkey spinal cord. Neuroscience 7: 1127–1139, 1982.
 218. Dockray, G. J. The physiology of cholecystokinin in brain and gut. Br. Med. Bull. 38: 253–258, 1982.
 219. Dodd, J., C. E. Jahr, and T. M. Jessell. Neurotransmitters and neuronal markers at sensory synapses in the dorsal horn. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 105–121.
 220. Doi, T., and I. Jurna. Intrathecal substance P depresses the tail‐flick response‐antagonism by naloxone. Naunyn‐Schmiedebergs Arch. Pharmakol. 317: 135–139, 1981.
 221. Doi, T., and I. Jurna. Analgesic effect of intrathecal morphine demonstrated in ascending nociceptive activity in the rat spinal cord and ineffectiveness of caerulein and cholecystokinin octapeptide. Brain Res. 234: 399–407, 1982.
 222. Dong, W. K., H. Ryu, and I. H. Wagman. Nociceptive responses of neurons in medial thalamus and their relationship to spinothalamic pathways. J. Neurophysiol. 41: 1592–1613, 1978.
 223. Dong, W. K., and I. H. Wagman. Modulation of nociceptive responses in the thalamus posterior group of nuclei. In: Advances in Pain Research and Therapy. Proceedings of the First World, Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976 vol. 1, p. 455–460.
 224. Dostrovsky, J. O., and J. W. Deakin. Periaquaeductal grey lesions reduce morphine analgesia in the rat. Neurosci. Lett. 4: 99–103, 1977.
 225. Dostrovsky, J. O., Y. Shah, and B. G. Gray. Descending inhibitory influences from periaqueductal gray, nucleus raphe magnus, and adjacent reticular formation. II. Effects on medullary dorsal horn nociceptive and nonnociceptive neurons. J. Neurophysiol. 49: 948–960, 1983.
 226. Drugan, R. C., J. W. Grau, S. F. Maier, J. Madden, and J. D. Barchas. Cross‐tolerance between morphine and the long‐term analgesic reaction to inescapable shock. Pharmacol. Biochem. Behav. 14: 677–682, 1981.
 227. Du, H. J., and Y. F. Chao. Localization of central structures involved in descending inhibitory effect of acupuncture on viscero‐somatic reflex discharges. Sci. Sin. 19: 137–148, 1976.
 228. Dubner, R., and G. J. Bennett. Spinal and trigeminal mechanisms of nociception. Annu. Rev. Neurosci. 6: 381–418, 1983.
 229. Dubner, R., M. A. Ruda, V. Miletic, M. J. Hoffert, G. J. Bennett, N. Nishikawa, and J. Coffield. Neural circuitry mediating nociception in the medullary and spinal dorsal horns. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 151–166.
 230. Dubuisson, D., M. Fitzgerald, and P. D. Wall. Ameboid receptive fields of cells in laminae 1, 2 and 3. Brain Res. 177: 376–378, 1979.
 231. Duggan, A. W. Inhibition in the spinal cord: its role in the response to injury. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 123–134.
 232. Duggan, A. W., J. Davies, and J. G. Hall. Effects of opiate agonists and antagonists on central neurones of the cat. J. Pharmacol. Exp. Ther. 196: 107–120, 1976.
 233. Duggan, A. W., and B. T. Griersmith. Inhibition of the spinal transmission of nociceptive information of supraspinal stimulation in the cat. Pain 6: 149–161, 1979.
 234. Duggan, A. W., B. T. Griersmith, and R. A. North. Morphine and supraspinal neurones: evidence that morphine decreases tonic descending inhibition in the anaesthetised cat. Br. J. Pharmacol. 69: 461–466, 1980.
 235. Duggan, A. W., and J. G. Hall. Morphine, naloxone and the responses of medial thalamic neurones of the cat. Brain Res. 122: 49–57, 1976.
 236. Duggan, A. W., J. G. Hall, and P. M. Headley. Morphine, enkephalin and the substantia gelatinosa. Nature London 264: 456–458, 1976.
 237. Duggan, A. W., J. G. Hall, and P. M. Headley. Suppression of transmission of nociceptive impulses by morphine: selective effects of morphine administered in the region of the substantia gelatinosa. Br. J. Pharmacol. 61: 65–76, 1977.
 238. Duggan, A. W., J. G. Hall, and P. M. Headley. Enkephalins and dorsal horn neurones of the cat: effects on responses to noxious and innocuous skin stimuli. Br. J. Pharmacol. 61: 399–408, 1977.
 239. Duggan, A. W., and S. M. Johnson. Narcotic antagonists: problems in the interpretation of their effect in laboratory and clinical research. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 309–321.
 240. Duggan, A. W., and R. A. North. Electrophysiology of opioids. Pharmacol. Rev. 35: 219–281, 1983.
 241. Duggan, A. W., and Z. Q. Zhao. Microelectrophoretic administration of naloxone near motoneurones fails to reproduce the effects of systemic naloxone in anaesthetized cats. Neurosci. Lett. 45: 305–310, 1984.
 242. Dunlap, K., and G. D. Fischbach. Neurotransmitter decrease the calcium component of sensory neurone action potentials. Nature London 276: 837–839, 1978.
 243. Edwards, S. B. Autoradiographic studies of the projections of the midbrain reticular formation: descending projections of nucleus cuneiformis. J. Comp. Neurol. 161: 341–358, 1975.
 244. Einspahr, F. J., and M. F. Piercey. Morphine depresses dorsal horn neuron responses to controlled noxious and nonnoxious cutaneous stimulation. J. Pharmacol. Exp. Ther. 213: 456–461, 1980.
 245. Elde, R., and T. Hökfelt. Localization of hypophysiotropic peptides and other biologically active peptides within the brain. Annu. Rev. Physiol. 41: 587–602, 1979.
 246. El‐Sobky, A., J. O. Dostrovsky, and P. D. Wall. Lack of effect of naloxone on pair perception in humans. Nature London 263: 783–784, 1976.
 247. Engberg, G., T. H. Svensson, S. Rosell, and K. Folkers. A synthetic peptide as an antagonist of substance P. Nature London 293: 222–223, 1981.
 248. Engberg, I., J. A. Flatman, and K. Kadzielawa. Lack of specificity of motoneurone responses to microiontophoretically applied phenolic amines. Acta Physiol. Scand. 96: 137–139, 1976.
 249. Eriksson, M., and B. Sjölund. Acupuncture‐like electroanalgesia in TNS‐resistant chronic pain. In: Sensory Functions of the Skin, edited by Y. Zotterman. New York: Pergamon, 1976, p. 575–580.
 250. Erulkar, S. D. The modulation of neurotransmitter release at synaptic junctions. Rev. Physiol. Biochem. Pharmacol. 98: 63–175, 1983.
 251. Fahrenkrug, J., and P. C. Emson. Vasoactive intestinal polypeptide: functional aspects. Br. Med. Bull. 38: 265–270, 1982.
 252. Ferreira, S. H. Prostaglandins: peripheral and central analgesia. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 627–634.
 253. Fessler, R. G., F. D. Brown, J. R. Rachlin, and S. Mullan. Elevated beta‐endorphin in cerebrospinal fluid after electrical brain stimulations: artifact of contrast infusion? Science 224: 1017–1019, 1984.
 254. Fields, H. L., and J. E. Adams. Pain after cortical injury relieved by electrical stimulation of the internal capsule. Brain 97: 169–178, 1974.
 255. Fields, H. L., and S. D. Anderson. Evidence that raphe spinal neurons mediate opiate and midbrain stimulation‐produced analgesia. Pain 5: 333–349, 1978.
 256. Fields, H. L., and A. I. Basbaum. Brainstem control of spinal pain transmission neurons. Annu. Rev. Physiol. 40: 217–248, 1978.
 257. Fields, H. L., A. I. Basbaum, C. H. Clanton, and S. D. Anderson. Nucleus raphe magnus inhibition of spinal cord dorsal horn neurons. Brain Res. 126: 441–453, 1977.
 258. Fields, H. L., C. H. Clanton, and S. D. Anderson. Somatosensory properties of spinoreticular neurons in the cat. Brain Res. 120: 49–66, 1977.
 259. Fields, H. L., P. C. Emson, B. K. Leigh, R. F. T. Gilbert, and L. L. Iversen. Multiple opiate receptor sites on primary afferent fibres. Nature London 284: 351–353, 1980.
 260. Finer, B. Mental mechanisms in the control of pain. In: Pain and Society, edited by H. W. Kosterlitz and L. Y. Terenius. Weinheim, West Germany: Chemie, 1980, p. 223–237. (Dahlem Konferenzen.)
 261. Fischer, J. A., S. M. Sagar, and J. B. Martin. Characterization and regional distribution of calcitonin binding sites in the rat brain. Life Sci. 29: 663–671, 1981.
 262. Fitzgerald, M. A study of the cutaneous afferent input to substantia gelatinosa. Neuroscience 6: 2229–2237, 1981.
 263. Fitzgerald, M. The contralateral input to the dorsal horn of the spinal cord in the decerebrated spinal rat. Brain Res. 236: 275–287, 1982.
 264. Fitzgerald, M. Alterations in the ipsi‐ and contralateral afferent inputs of dorsal horn cells produced by capsaicin treatment of one sciatic nerve in the rat. Brain Res. 248: 97–107, 1982.
 265. Fitzgerald, M. Capsaicin and sensory neurones—a review. Pain 15: 109–130, 1983.
 266. Fitzgerald, M., and P. D. Wall. The laminar organization of dorsal horn cells responding to peripheral C‐fibre stimulation. Exp. Brain Res. 41: 36–44, 1980.
 267. Fitzgerald, M., and C. J. Woolf. The stereospecific effect of naloxone on rat dorsal horn neurones, inhibition in superficial laminae and excitation in deeper laminae. Pain 9: 293–306, 1980.
 268. Fitzgerald, M., and C. J. Woolf. The functional properties of identified neurones in the dorsal columns and the superficial laminae of the dorsal horn of the rat spinal cord (Abstract). J. Physiol. London 332: 23P, 1982.
 269. Fleetwood‐Walker, S. M., and J. H. Coote. Contribution of noradrenaline, dopamine and adrenaline‐containing axons to the innervation of different regions of the spinal cord of the cat. Brain Res. 206: 95–106, 1981.
 270. Fock, S., and S. Mense. Excitatory effects of 5‐hydroxytryptamine, histamine and potassium ions on muscular group IV afferent units: a comparison with bradykinin. Brain Res. 105: 459–469, 1976.
 271. Folkers, K., J. Hörig, S. Rosell, and K. Björkroth. Chemical design of antagonists of substance P. Acta Physiol. Scand. 111: 505–506, 1981.
 272. Foreman, R. D., A. E. Applebaum, J. E. Beall, D. L. Trevino, and W. D. Willis. Responses of primate spinothalamic tract neurons to electrical stimulation of hindlimb peripheral nerves. J. Neurophysiol. 38: 132–145, 1975.
 273. Foreman, R. D., J. E. Beall, A. E. Applebaum, J. D. Coulter, and W. D. Willis. Effects of dorsal column stimulation on primate spinothalamic tract neurons. J. Neurophysiol. 39: 534–546, 1976.
 274. Foreman, R. D., J. E. Beall, A. E. Applebaum, J. D. Coulter, and W. D. Willis. Inhibition of primate spinothalamic tract neurons by electrical stimulation of dorsal column or peripheral nerve. In: Advances in Pain Research and Therapy. Proceedings of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976, vol. 1, p. 405–410.
 275. Foreman, R. D., M. B. Hancock, W. D. Willis. Responses of spinothalamic tract cells in the thoracic spinal cord of the monkey to cutaneous and visceral inputs. Pain 11: 149–162, 1981.
 276. Foreman, R. D., R. F. Schmidt, and W. D. Willis. Convergence of muscle and cutaneous input onto primate spinothalamic tract neurons. Brain Res. 124: 555–560, 1977.
 277. Foreman, R. D., R. F. Schmidt, and W. D. Willis. Effects of mechanical and chemical stimulation of fine muscle afferents upon primate spinothalamic tract cells. J. Physiol. London 286: 215–231, 1979.
 278. Foster, R. W., and A. G. Ramage. The action of some chemical irritants on somatosensory receptors of the cat. Neuropharmacology 20: 191–198, 1981.
 279. Fox, E. J., and R. Melzack. Transcutaneous electrical stimulation and acupuncture: comparison of treatment for low‐back pain. Pain 2: 141–148, 1976.
 280. Fox, S., K. Krnjevic, M. E. Morris, E. Puil, and R. Werman. Action of baclofen on mammalian synaptic transmission. Neuroscience 3: 495–515, 1978.
 281. Fredericksen, R. C. A., V. Burgis, and J. C. Edwards. Hyperalgesia induced by naloxone follows diurnal rhythm in responsivity to painful stimuli. Science 198: 756–758, 1977.
 282. Fredericksen, R. C. A., V. Burgis, C. E. Harrell, and J. D. Edwards. Dual actions of substance P on nociception: possible role of endogenous opioids. Science 199: 1359–1362, 1978.
 283. Fredericksen, R. C. A., and F. H. Norris. Enkephalin‐induced depression of single neurons in brain areas with opiate receptors‐antagonism by naloxone. Science 194: 440–442, 1976.
 284. Frid, M., G. Singer, T. Ori, and C. Rana. Reactions of ischemic pain: interaction between individual, situational and naloxone effects. Psychopharmacology 73: 116–119, 1981.
 285. Fry, J. P., A. Herz, and W. Zieglgänsberger. A demonstration of naloxone‐precipitated opiate withdrawal on single neurones in the morphine tolerant/dependent rat brain. Br. J. Pharmacol. 68: 585–592, 1980.
 286. Fu, T. C., S. P. Halenda, and W. L. Dewey. The effect of hypophysectomy on acupuncture analgesia. Brain Res. 202: 33–39, 1980.
 287. Fuxe, K., S.‐O. Ogren, L. F. Agnati, G. Jonsson, and J.‐A. Gustafsson. 5,7‐dihydroxytryptamine as a tool to study the functional role of central 5‐hydroxytryptamine neurons. Ann. NY Acad. Sci. 305: 346–369, 1978.
 288. Galeano, C., and C. Y. Leung. Has acupuncture an analgesic effect in the rabbit? Pain 4: 265–271, 1978.
 289. Galeano, C., C. Y. Leung, R. Robitaille, and T. Roy‐Chabot. Acupuncture and analgesia in rabbits. Pain 6: 71–81, 1979.
 290. Gallager, D. W., and A. Pert. Afferents to brain stem nuclei (brain stem raphe, nucleus reticularis caudalis and nucleus gigantocellularis) in the rat as demonstrated by microiontophoretically applied horseradish peroxidase. Brain Res. 144: 257–275, 1978.
 291. Gamse, R., P. Holzer, and F. Lembeck. Indirect evidence for presynaptic location of opiate receptors on chemosensitive primary sensory neurones. Naunyn‐Schmiedeberg's Arch. Pharmacol. 308: 281–285, 1979.
 292. Gamse, R., P. Holzer, and F. Lembeck. Decrease of substance P in primary afferent neurones and impairment of neurogenic plasma extravasation by capsaicin. Br. J. Pharmacol. 68: 207–213, 1980.
 293. Gamse, R., U. Petsche, F. Lembeck, and G. Jancso. Capsaicin applied to peripheral nerve inhibits axoplasmic transport of substance P and somatostatin. Brain Res. 239: 447–462, 1982.
 294. Garau, L., M. L. Mulas, and G. Pepeu. The influence of raphe lesions on the effect of morphine on nociception and cortical ACh output. Neuropharmacology 14: 259–263, 1975.
 295. Gautron, M., and G. Guilbaud. Somatic responses of ventrobasal thalamic neurones in polyarthritic rats. Brain Res. 237: 459–471, 1982.
 296. Gäwhiler, B. H. Excitatory action of opioid peptides and opiates on cultured hippocampal pyramidal cells. Brain Res. 194: 193–203, 1980.
 297. Gebhart, G. F. Opiate and opioid peptide effects on brain stem neurons: relevance to nociception and antinociceptive mechanisms. Pain 12: 93–140, 1982.
 298. Gebhart, G. F., J. Sandkühler, J. G. Thalhammer, and M. Zimmermann. Quantitative comparison of inhibition in spinal cord of nociceptive information by stimulation in periaqueductal gray or nucleus raphe magnus of the cat. J. Neurophysiol. 50: 1433–1445, 1983.
 299. Gebhart, G. F., J. Sandkühler, J. G. Thalhammer, and M. Zimmermann. Inhibition of spinal nociceptive information by stimulation in midbrain of the cat is blocked by lidocaine microinjected in nucleus raphe magnus and medullary reticular formation. J. Neurophysiol. 50: 1446–1459, 1983.
 300. Gebhart, G. F., and J. R. Toleikis. An evaluation of stimulation‐produced analgesia in the cat. Exp. Neurol. 62: 570–579, 1978.
 301. Gent, J. P., and J. H. Wolstencroft. Effects of methionine‐enkephalin and leucine‐enkephalin compared with those of morphine on brainstem neurones in cat. Nature London 261: 426–427, 1976.
 302. Gentleman, P., M. Parenti, J. W. Commissiong, and N. H. Neff. Dopamine‐activated adenyl cyclase of spinal cord: supersensitivity following transection of the cord. Brain Res. 210: 271–275, 1981.
 303. Gerhart, K. D., T. K. Wilcox, J. M. Chung, and W. D. Willis. Inhibition of nociceptive and nonnociceptive responses of primate spinothalamic cells by stimulation in medial brain stem. J. Neurophysiol. 45: 121–136, 1981.
 304. Gerhart, K. D., R. P. Yezierski, Z. R. Fang, and W. D. Willis. Inhibition of primate spinothalamic tract neurons by stimulation in ventral posterior lateral (VPLc) thalamic nucleus: possible mechanisms. J. Neurophysiol. 49: 406–423, 1983.
 305. Gerhart, K. D., R. P. Yezierski, G. J. Giesler, Jr., and W. D. Willis. Inhibitory receptive fields of primate spinothalamic tract cells. J. Neurophysiol. 46: 1309–1325, 1981.
 306. Gerhart, K. D., R. P. Yezierski, T. K. Wilcox, A. E. Grossman, and W. D. Willis. Inhibition of primate spinothalamic tract neurons by stimulation in ipsilateral or contralateral ventral posterior lateral (VPLc) thalamic nucleus. Brain Res. 229: 514–519, 1981.
 307. Gerhart, K. D., R. P. Yezierski, T. K. Wilcox, and W. D. Willis. Inhibition of primate spinothalamic tract neurons by stimulation in periaqueductal gray or adjacent midbrain reticular formation. J. Neurophysiol. 51: 450–466, 1984.
 308. Giesler, G. J., Jr., J. T. Cannon, G. Urca, and J. C. Liebeskind. Long ascending projections from substantia gelatinosa Rolandi and the subjacent dorsal horn in the rat. Science 202: 984–986, 1978.
 309. Giesler, G. J., Jr., K. D. Gerhart, R. P. Yezierski, T. K. Wilcox, and W. D. Willis. Postsynaptic inhibition of primate spinothalamic neurons by stimulation in nucleus raphe magnus. Brain Res. 204: 184–188, 1981.
 310. Giesler, G. J., Jr., D. Menétrey, G. Guilbaud, and J. M. Besson. Lumbar cord neurons at the origin of the spinothalamic tract in the rat. Brain Res. 118: 320–324, 1976.
 311. Giesler, G. J., Jr., R. L. Nahin, and A. M. Madsen. Postsynaptic dorsal column pathway of the rat. I. Anatomical studies. J. Neurophysiol. 51: 260–275, 1984.
 312. Giesler, G. J., Jr., H. R. Spiel, and W. D. Willis. Organization of spinothalamic tract axons within the rat spinal cord. J. Comp. Neurol. 195: 243–252, 1981.
 313. Giesler, G. J., Jr., R. P. Yezierski, K. D. Gerhart, and W. D. Willis. Spinothalamic tract neurons that project to medial and/or lateral thalamic nuclei: evidence for a physiologically novel population of spinal cord neurons. J. Neurophysiol. 46: 1285–1308, 1981.
 314. Gilbert, R. F. T., P. C. Emson, S. P. Hunt, G. W. Bennett, C. A. Marsden, B. E. B. Sandberg, H. W. M. Steinbusch, and A. A. J. Verhofstad. The effects of monoamine neurotoxins on peptides in the rat spinal cord. Neuroscience 7: 69–87, 1982.
 315. Gintzler, A. R. Endorphin mediated increases in pain threshold during pregnancy. Science 210: 193–195, 1980.
 316. Gintzler, A. R., L. C. Peters, and B. R. Komisaruk. Attenuation of pregnancy‐induced analgesia by hypogastric neuroectomy in rats. Brain Res. 277: 186–188, 1983.
 317. Glazer, E. J., and A. I. Basbaum. Immunohistochemical localization of leucine‐enkephalin in the spinal cord of the cat: enkephalin‐containing marginal neurons and pain modulation. J. Comp. Neurol. 196: 377–389, 1981.
 318. Glazer, E. J., and A. I. Basbaum. Axons which take up [3H]serotonin are presynaptic to enkephalin immunoreactive neurons in cat dorsal horn. Brain Res. 298: 386–391, 1984.
 319. Gobel, S. Golgi studies of the substantia gelatinosa neurons in the spinal trigeminal nucleus. J. Comp. Neurol. 162: 397–416, 1975.
 320. Gobel, S. Neural circuitry in substantia gelatinosa of Rolando: anatomical insights. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress on Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 175–195.
 321. Gobel, S., W. M. Falls, G. J. Bennett, M. Abdelmoumene, H. Hayashi, and E. Humphrey. An EM analysis of the synaptic connections of horseradish peroxidase‐filled stalked cells and islet cells in the substantia gelatinosa of adult cat spinal cord. J. Comp. Neurol. 194: 781–807, 1980.
 322. Godfraind, J. M., T. M. Jessell, J. S. Kelly, R. M. McBurney, A. W. Mudge, and M. Yamamoto. Capsaicin prolongs action potential duration in cultured sensory neurones (Abstract). J. Physiol. London 312: 32P–33P, 1981.
 323. Goldberger, S. M., and B. Tursky. Modulation of shock‐elicited pain by acupuncture and suggestion. Pain 2: 417–429, 1976.
 324. Goldfarb, J., and J. W. Hu. Enhancement of reflexes by naloxone in spinal cats. Neuropharmacology 15: 785–792, 1976.
 325. Goldstein, A. Endorphins and pain. A critical review. In: Mechanisms of Pain and Analgetic Compounds, edited by R. F. Beers and E. G. Bassett. New York: Raven, 1979, p. 249–262. (Miles Int. Symp. 11.)
 326. Goldstein, A., and E. R. Hilgard. Failure of the opiate antagonist naloxone to modify hypnotic analgesia. Proc. Natl. Acad. Sci. USA 72: 2041–2043, 1975.
 327. Gonzales‐Vegas, J. A. Nigro‐reticular pathway in the rat: an intracellular study. Brain Res. 207: 170–173, 1981.
 328. Gracely, R. H. Psychophysical assessment of human pain. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress in Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 805–824.
 329. Gracely, R. H., R. Dubner, and P. A. McGrath. Narcotic analgesia: fentanyl reduces the intensity not the unpleasantness of painful tooth pulp sensations. Science 203: 1261–1263, 1979.
 330. Gracely, R. H., R. Dubner, P. J. Wolskee, and W. R. Deeter. Placebo and naloxone can alter postsurgical pain by separate mechanisms. Nature London 306: 264–265, 1983.
 331. Gracely, R. H., P. McGrath, and R. Dubner. Validity and sensitivity of ratio scales of sensory and affective verbal pain descriptors: manipulation of affect by diazepam. Pain 2: 19–29, 1976.
 332. Gracely, R. H., P. McGrath, and R. Dubner. Ratio scales of sensory and affective verbal pain descriptors. Pain 5: 5–18, 1978.
 333. Grau, J. W., R. L. Hyson, S. F. Maier, J. Madden, and J. D. Barchas. Long‐term stress‐induced analgesia and activation of the opiate system. Science 213: 1409–1410, 1981.
 334. Gray, B. G., and J. O. Dostrovsky. Descending inhibitory influences from periaqueductal gray, nucleus raphe magnus, and adjacent reticular formation. I. Effects on lumbar spinal cord nociceptive and nonnociceptive neurons. J. Neurophysiol. 49: 932–947, 1983.
 335. Gregor, M., and M. Zimmermann. Characteristics of spinal neurones responding to cutaneous myelinated and unmyelinated fibres. J. Physiol. London 221: 555–576, 1972.
 336. Grevert, P., and A. Goldstein. Effects of naloxone on experimentally induced ischemic pain and on mood in human subjects. Proc. Natl. Acad. Sci. USA 74: 1291–1294, 1977.
 337. Grevert, P., and A. Goldstein. Some effects of naloxone on behavior in the mouse. Psychopharmacology 53: 111–113, 1977.
 338. Grevert, P., and A. Goldstein. Endorphins: naloxone fails to alter experimental pain or mood in humans. Science 199: 1093–1095, 1978.
 339. Griersmith, B. T., and A. W. Duggan. Prolonged depression of spinal transmission of nociceptive information by 5‐HT administered in the substantia gelatinosa: antagonism by methysergide. Brain Res. 187: 231–236, 1980.
 340. Griersmith, B. T., A. W. Duggan, and R. A. North. Methysergide and supraspinal inhibition of the spinal transmission of nociceptive information in the anesthetized cat. Brain Res. 204: 147–158, 1981.
 341. Grumbach, L. The prediction of analgesic activity in man by animal testing. In: Pain, edited by R. S. Knighton and P. R. Dumke. Boston, MA: Little, Brown, 1966, p. 162–182.
 342. Guilbaud, G., J. M. Besson, J. L. Oliveras, and J. C. Liebeskind. Suppression of LSD of the inhibitory effect exerted by dorsal raphe stimulation on certain spinal cord interneurons in the cat. Brain Res. 61: 417–422, 1973.
 343. Guilbaud, G., D. Caille, J. M. Besson, and G. Benelli. Single unit activities in ventral posterior and posterior group thalamic nuclei during nociceptive and non‐nociceptive stimulation in the cat. Arch. Ital. Biol. 115: 38–56, 1977.
 344. Guilbaud, G., J. L. Oliveras, G. Giesler, and J. M. Besson. Effects induced by stimulation of the centralis inferior nucleus of the raphe on dorsal horn interneurones in the cat's spinal cord. Brain Res. 126: 355–360, 1977.
 345. Guilbaud, G., M. Peschanski, and J. M. Besson. Experimental data related to nociception and pain at the supraspinal level. In: Textbook of Pain, edited by P. D. Wall and R. Melzack. Edinburgh: Churchill Livingstone, 1984, p. 110–118.
 346. Guilbaud, G., M. Peschanski, M. Gautrón, and D. Binder. Neurones responding to noxious stimulation in VB complex and caudal adjacent regions in the thalamus of the rat. Pain 8: 303–318, 1980.
 347. Guilbaud, G., M. Peschanski, M. Gautron, and D. Binder. Responses of neurons of the nucleus raphe magnus to noxious stimuli. Neurosci. Lett. 17: 149–154, 1980.
 348. Guillemin, R., T. Vargo, J. Rossier, S. Minick, N. Ling, C. Rivier, W. Vale, and F. Bloom. Beta‐endorphin and adrenocorticotropin are secreted concomitantly by the pituitary gland. Science 197: 1367–1369, 1977.
 349. Guyenet, P. G., and G. K. Aghajanian. ACh, substance P and met‐enkephalin in the locus coeruleus: pharmacological evidence for independent sites of action. Eur. J. Pharmacol. 53: 319–328, 1979.
 350. Gybels, J. M. Electrical stimulation of the central gray for pain relief in humans: a critical review. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress on Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 499–509.
 351. Gybels, J. M., H. O. Handwerker, and J. Van Hees. A comparison between the discharges of human nociceptive fibres and the subject's ratings of his sensation. J. Physiol. London 292: 193–206, 1979.
 352. Ha, H., E. C. Tan, H. Fukunaga, and O. Aochi. Naloxone reversal of acupuncture analgesia in the monkey. Exp. Neurol. 73: 298–303, 1981.
 353. Haber, L. H., R. F. Martin, A. B. Chatt, and W. D. Willis. Effects of stimulation in nucleus reticularis gigantocellularis on the activity of spinothalamic tract neurons in the monkey. Brain Res. 153: 163–168, 1978.
 354. Haber, L. H., R. F. Martin, J. M. Chung, and W. D. Willis. Inhibition and excitation of primate spinothalamic tract neurons by stimulation in region of nucleus reticularis gigantocellularis. J. Neurophysiol. 43: 1578–1593, 1980.
 355. Haber, L. H., B. D. Moore, and W. D. Willis. Electrophysiological response properties of spinoreticular neurons in the monkey. J. Comp. Neurol. 207: 75–84, 1982.
 356. Haigler, H. J. Morphine: ability to block neuronal activity evoked by a nociceptive stimulus. Life Sci. 19: 841–858, 1976.
 357. Haigler, H. J. Morphine: effects on serotonergic neurons and neurons in areas with a serotonergic input. Eur. J. Pharmacol. 51: 361–376, 1978.
 358. Haigler, H. J. Serotonergic receptors in the central nervous system. In: Neurotransmitter Receptors. Biogenic Amines, edited by H. D. Yamamura and S. J. Enna. London: Chapman & Hall, 1981, pt. 2, p. 3–70.
 359. Hall, J. G., A. W. Duggan, C. R. Morton, and S. M. Johnson. The location of brainstem neurones tonically inhibiting dorsal horn neurones of the cat. Brain Res. 244: 215–222, 1982.
 360. Hallin, R. G., and H. E. Torebjörk. Studies on cutaneous A‐ and C‐fibre afferents, skin nerve blocks and perception. In: Sensory Functions of the Skin in Primates, With Special Reference to Man, edited by Y. Zotterman. New York: Pergamon, 1976, p. 137–148.
 361. Hammond, D. L., R. A. Levy, and H. K. Proudfit. Hypoalgesia following microinjection of noradrenergic antagonists in the nucleus raphe magnus. Pain 9: 85–101, 1980.
 362. Han, J. S., J. Tang, M. F. Ren, Z. F. Zhou, S. G. Fan, and X. C. Qiu. Central neurotransmitters and acupuncture analgesia. Am. J. Chin. Med. 8: 331–348, 1980.
 363. Hanbauer, I., S. Govoni, E. A. Majane, H. T. Y. Yang, and E. Costa. In vivo regulation of the release of metenkephalin‐like peptides from dog adrenal medulla. Adv. Biochem. Psychopharmacol. 33: 209–215, 1982.
 364. Hancock, M. B., R. D. Foreman, and W. D. Willis. Convergence of visceral and cutaneous input onto spinal thalamic tract cells in the thoracic spinal cord of the cat. Exp. Neurol. 47: 240–248, 1975.
 365. Handwerker, H. O. Influences of algogenic substances and prostaglandins on the discharges of unmyelinated cutaneous nerve fibers identified as nociceptors. In: Advances in Pain Research and Therapy. Proceedings of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1975, vol. 1, p. 41–45.
 366. Handwerker, H. O., A. Iggo, and M. Zimmermann. Segmental and supraspinal actions on dorsal horn neurones responding to noxious and non‐noxious skin stimuli. Pain 1: 147–165, 1975.
 367. Hanley, M. R., B. E. B. Sandberg, C. M. Lee, L. L. Iversen, D. E. Brundish, and R. Wade. Specific binding of 3H‐substance P to rat brain membranes. Nature London 286: 810–812, 1980.
 368. Harmar, A., and P. Keen. Synthesis and central and peripheral axonal transport of substance P in a dorsal root ganglion‐nerve preparation in vitro. Brain Res. 231: 379–385, 1982.
 369. Hayes, A. G., and M. B. Tyers. Effects of capsaicin on nociceptive heat, pressure and chemical thresholds and on substance P levels in the rat. Brain Res. 189: 561–564, 1980.
 370. Hayes, N. L., and A. Rustioni. Descending projections from brainstem and sensorimotor cortex to spinal enlargements in the cat. Exp. Brain Res. 41: 89–107, 1981.
 371. Hayes, R. L., G. J. Bennett, and D. J. Mayer. Acupuncture, pain and signal detection theory. Science 189: 65–66, 1975.
 372. Hayes, R. L., G. J. Bennett, P. G. Newlon, and D. J. Mayer. Behavioral and physiological studies of non‐narcotic analgesia in the rat elicited by certain environmental stimuli. Brain Res. 155: 69–90, 1978.
 373. Hayes, R. L., Y. Katayama, L. R. Watkins, and D. P. Becker. Bilateral designs of the dorsolateral funiculus of the cat spinal cord: effects on basal nociceptive reflexes and nociceptive suppression produced by cholinergic activation of the pontine parabrachial region. Brain Res. 311: 267–280, 1984.
 374. Hayes, R. L., P. G. Newlon, J. A. Rosecrans, and D. J. Mayer. Reduction of stimulation‐produced analgesia by lysergic acid diethylamide, a depressor of serotonergic neural activity. Brain Res. 122: 367–372, 1977.
 375. Hayes, R. L., D. D. Price, G. L. Bennett, G. L. Wilcox, and D. J. Mayer. Differential effects of spinal cord lesions on narcotic and non‐narcotic suppression of nociceptive reflexes. Further evidence for the physiological multiplicity of pain modulation. Brain Res. 155: 91–101, 1979.
 376. Hayes, R. L., D. D. Price, and R. Dubner. Behavioral and physiological studies of sensory coding and modulation of trigeminal nociceptive input. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress on Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 219–243.
 377. Hayes, R. L., D. D. Price, M. A. Ruda, and R. Dubner. Suppression of nociceptive responses in the primate by electrical stimulation of the brain or morphine administration: behavioural and electrophysiological comparison. Brain Res. 167: 417–421, 1979.
 378. Headley, P. M., A. W. Duggan, and B. T. Griersmith. Selective reduction by noradrenaline and 5‐hydroxytryptamine of nociceptive responses of cat dorsal horn neurones. Brain Res. 145: 185–189, 1978.
 379. Helke, C. J. Neuroanatomical location of substance P: implication for central cardiovascular control. Peptides 3: 479–483, 1982.
 380. Henry, J. L. Effects of substance P on functionally identified units in cat spinal cord. Brain Res. 114: 439–451, 1976.
 381. Henry, J. L. Naloxone excites nociceptive units in the lumbar dorsal horn of the spinal cat. Neuroscience 4: 1485–1491, 1979.
 382. Henry, J. L. Naloxone excitation of spinal dorsal horn units shows diurnal variation. In: Exogenous and Endogenous Opiate Agonists and Antagonists, edited by E. L. Way. New York: Pergamon, 1980, p. 191–194.
 383. Henry, J. L. Effects of intravenously administered enantiomers of baclofen on functionally identified unit in lumbar dorsal horn of the spinal cat. Neuropharmacology 21: 1073–1083, 1982.
 384. Henry, J. L. Electrophysiological studies on the neuroactive properties of neurotensin. In: Neurotensin: A Brain and Gastrointestinal Peptide, edited by C. B. Nemeroff and A. J. Prange, Jr. New York: NY Acad. Sci., 1982, p. 216–227.
 385. Henry, J. L. Pharmacological studies on the prolonged depressant effects of baclofen on lumbar dorsal horn unit in the cat. Neuropharmacology 21: 1085–1093, 1982.
 386. Henry, J. L. Relation of substance P to pain transmission: neurophysiological evidence. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 206–224. (Ciba Found. Symp. 91.)
 387. Henry, J. L., and Y. Ben‐Ari. Actions of the p‐chlorophenyl derivative of GABA, lioresal, on nociceptive and non‐nociceptive units in the spinal cord of the cat. Brain Res. 117: 540–544, 1976.
 388. Henry, J. L., K. Krnjevic, and M. E. Morris. Substance P and spinal neurones. Can. J. Physiol. Pharmacol. 53: 423–432, 1975.
 389. Hentall, I. A novel class of unit in the substantia gelatinosa of the spinal cat. Exp. Neurol. 57: 792–806, 1977.
 390. Hentall, I. D., and H. L. Fields. Segmental and descending influences on intraspinal thresholds of single C‐fibers. J. Neurophysiol. 42: 1527–1537, 1979.
 391. Herkenham, M., and C. B. Pert. In vitro autoradiography of opiate receptors in rat brain suggest loci of “opiatergic” pathways. Proc. Natl. Acad. Sci. USA 77: 5532–5536, 1980.
 392. Herz, A. Wirkungen des Arecolins auf das zentrale Nervensystem. Naunyn‐Schmiedeberg's Arch. Exp. Pathol. Pharmacol. 242: 414–429, 1962.
 393. Herz, A., K. Albus, J. Metys, P. Schubert, and H. Teschemacher. On the central sites for the antinociceptive action of morphine and fentanyl. Neuropharmacology 9: 539–551, 1970.
 394. Hilgard, E. R. The alleviation of pain by hypnosis. Pain 1: 213–231, 1975.
 395. Hill, D. R., and N. G. Bowery. 3H‐baclofen and 3H‐GABA bind to bicuculline‐insensitive sites in rat brain. Nature London 290: 149–152, 1981.
 396. Hill, R. G. The status of naloxone in the identification of pain control mechanisms operated by endogenous opioids. Neurosci. Lett. 21: 217–222, 1981.
 397. Hill, R. G., and S. J. Ayliffe. The antinociceptive effect of vaginal stimulation in the rat is reduced by naloxone. Pharmacol. Biochem. Behav. 14: 631–632, 1981.
 398. Hill, R. G., M. Hoddinott, and P. M. Keen. Action of substance P on trigeminal nucleus caudalis neurons in capsaicin treated rats. In: Neuropeptides and Neuronal Transmission, edited by C. Ajmon‐Marson and W. Z. Traczyk. New York: Raven, 1980, p. 31–41.
 399. Hill, R. G., and C. M. Pepper. The effects of morphine and met‐enkephalin on nociceptive neurones in the rat thalamus. Br. J. Pharmacol. 58: 459–460, 1976.
 400. Hill, R. G., and C. M. Pepper. The depression of thalamic nociceptive neurones by D‐ala2,‐D‐leu5‐enkephalin. Eur. J. Pharmacol. 47: 223–225, 1978.
 401. Hill, R. G., and C. M. Pepper. Selective effects of morphine on the nociceptive responses of thalamic neurones in the rat. Br. J. Pharmacol. 64: 137–143, 1978.
 402. Hill, R. G., C. M. Pepper, and J. F. Mitchell. Depression of nociceptive and other neurones in the brain by iontophoretically applied met‐enkephalin. Nature London 262: 604–606, 1976.
 403. Hiller, J. M., E. J. Simon, S. M. Crain, and E. R. Peterson. Opiate receptors in cultures of fetal mouse dorsal root ganglia (DRG) and spinal cord: predominance in DRG neurites. Brain Res. 145: 396–400, 1978.
 404. Hillman, P., and P. D. Wall. Inhibitory and excitatory factors influencing the receptive fields of lamina 5 spinal cord cells. Exp. Brain Res. 9: 284–306, 1969.
 405. Hiss, E., and S. Mense. Evidence for the existence of different receptor sites for algesic agents at the endings of muscular group IV afferent units. Pfluegers Arch. 362: 141–146, 1976.
 406. Hockfield, S., and S. Gobel. Neurons in and near nucleus caudalis with long ascending projection axons demonstrated by retrograde labeling with horseradish peroxidase. Brain Res. 139: 333–339, 1978.
 407. Hodge, C. J., Jr., A. V. Apkarian, R. Stevens, G. Vogelsang, and H. J. Wisnicki. Locus coeruleus modulation of dorsal horn unit responses to cutaneous stimulation. Brain Res. 204: 415–420, 1981.
 408. Hoffman, D. S., R. Dubner, R. L. Hayes, and T. P. Medlin. Neuronal activity in medullary dorsal horn of awake monkeys trained in a thermal discrimination task. I. Responses to innocuous and noxious thermal stimuli. J. Neurophysiol. 46: 409–427, 1981.
 409. Hökfelt, T., R. Elde, O. Johansson, L. Terenius, and L. Stein. The distribution of enkephalin‐immunoreactive cell bodies in the rat central nervous system. Neurosci. Lett. 5: 25–31, 1977.
 410. Hökfelt, T., K. Fuxe, M. Goldstein, and O. Johansson. Immunohistochemical evidence for the existence of adrenaline neurons in the rat brain. Brain Res. 66: 235–251, 1974.
 411. Hökfelt, T., O. Johansson, and M. Goldstein. Chemical anatomy of the brain. Science 225: 1326–1334, 1984.
 412. Hökfelt, T., O. Johansson, A. Ljungdahl, J. M. Lundberg, and J. M. Schultzberg. Peptidergic neurones. Nature London 284: 515–521, 1980.
 413. Hökfelt, T., J. O. Kellerth, G. Nilsson, and B. Pernow. Experimental immunohistochemical studies on the localization and distribution of substance P in cat primary sensory neurones. Brain Res. 100: 235–252, 1975.
 414. Hökfelt, T., J. O. Kellerth, G. Nilsson, and B. Pernow. Substance P: localization in the central nervous system and in some primary sensory neurons. Science 190: 889–890, 1975.
 415. Hökfelt, T., A. Ljungdahl, H. Steinbusch, A. Verhofstad, G. Nilsson, E. Brodin, B. Pernow, and M. Goldstein. Immunohistochemical evidence of substance P‐like immunoreactivity in some 5‐hydroxytryptamine‐containing neurons in the rat central nervous system. Neuroscience 3: 517–538, 1978.
 416. Hökfelt, T., L. Skirboll, J. M. Lundberg, C.‐J. Dalsgaard, O. Johansson, B. Pernow, and G. Jancso. Neuropeptides and pain pathways. In: Advances in Pain Research and Therapy, Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 227–246.
 417. Holaday, J. W. Cardiovascular effects of endogenous opiate systems. Annu. Rev. Pharmacol. Toxicol. 23: 541–594, 1983.
 418. Höllt, V. Multiple endogenous opioid peptides. Trends Neurosci. 6: 24–26, 1983.
 419. Holmdahl, G., R. Hakanson, S. Leander, S. Rosell, K. Folkers, and F. Sundler. A substance P antagonist D‐Pro2‐D‐Tryp7,9 SP, inhibits inflammatory responses in the rabbit eye. Science 214: 1029–1031, 1983.
 420. Honda, C. N., S. Mense, and E. R. Perl. Neurons in ventrobasal region of cat thalamus selectively responsive to noxious mechanical stimulation. J. Neurophysiol. 49: 662–673, 1983.
 421. Hosobuchi, Y. The current status of analgesic brain stimulation. Acta Neurochir. Suppl. 30: 219–227, 1980.
 422. Hosobuchi, Y., J. E. Adams, and H. L. Fields. Chronic thalamic and internal capsular stimulation for the control of facial anesthesia dolorosa and dysesthesia of thalamic syndrome. Adv. Neurol. 4: 783–787, 1974.
 423. Hosobuchi, Y., J. E. Adams, and R. Linchitz. Pain relief by electrical stimulation of the central gray matter in humans and its reversal by naloxone. Science 197: 183–186, 1977.
 424. Hosobuchi, Y., J. E. Adams, and B. Rutkin. Chronic thalamic stimulation for the control of facial anesthesia dolorosa. Arch. Neurol. 29: 158–161, 1973.
 425. Hosobuchi, Y., S. Lamb, and D. Bascom. Tryptophan loading may reverse tolerance to opiate analgesics in humans: preliminary report. Pain 9: 161–169, 1980.
 426. Hosobuchi, Y., J. Rossier, F. E. Bloom, and R. Guillemin. Stimulation of human periaqueductal gray for pain relief increases immunoreactive beta‐endorphin in ventricular fluid. Science 203: 279–281, 1979.
 427. Howe, J. R., J.‐Y. Wang, and T. L. Yaksh. Selective antagonism of the antinociceptive effect of intrathecally applied alpha‐adrenergic agonists by intrathecal prazosin and intrathecal yohimbine. J. Pharmacol. Exp. Ther. 224: 552–558, 1983.
 428. Howe, J. R., and T. L. Yaksh. Changes in sensitivity to intrathecal norepinephrine and serotonin after 6‐hydroxydopamine (6‐OHDA),5,6‐dihydroxytryptamine (5,6‐DHT) or repeated monoamine administration. J. Pharmacol. Exp. Ther. 220: 311–321, 1982.
 429. Hughes, J., T. W. Smith, H. W. Kosterlitz, L. A. Fothergill, B. A. Morgan, and H. R. Morris. Identification of two related penta peptides from the brain with potent opiate agonist activity. Nature London 258: 557–579, 1975.
 430. Hunt, S. P., J. S. Kelly, P. C. Emson, J. R. Kimmel, R. J. Miller, and J.‐Y. Wu. An immunohistochemical study of neuronal populations containing neuropeptides or gamma‐amino‐butyrate within the superficial layers of the rat dorsal horn. Neuroscience 6: 1883–1898, 1981.
 431. Hunt, S. P., J. I. Nagy, and M. Ninkovic. Peptides and the organization of the dorsal horn. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 159–178.
 432. Iggo, A. Activation of cutaneous nociceptors and their actions on dorsal horn neurons. In: Advances in Neurology. International Symposium on Pain, edited by J. J. Bonica. New York: Raven, 1974, vol. 4, p. 1–9.
 433. Iggo, A. Segmental neurophysiology of pain control. In: Pain and Society, edited by H. W. Kosterlitz and L. Y. Terenius. Weinheim, West Germany: Chemie, 1980, p. 123–140. (Dahlem Konferenzen.)
 434. Iggo, A., G. Guilbaud, and R. Tegner. Sensory mechanisms in arthritic rat joints. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 83–93.
 435. Ireson, J. D. A comparison of the antinociceptive actions of cholinomimetic and morphine‐like drugs. Br. J. Pharmacol. 40: 92–101, 1970.
 436. Itoga, E., S. Kito, T. Kishida, N. Yanaihara, N. Ogawa, and J. Wakabayashi. Ultrastructural localization of neuropeptides in the rat primary sensory neurones. Acta Histochem. Cytochem. 13: 407–420, 1980.
 437. Iversen, L. L., M. R. Hanley, B. E. B. Sandberg, C.‐M. Lee, R. D. Pinnock, and S. P. Watson. Substance P receptors in the nervous system and possible receptor subtypes. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 186–205. (Ciba Found. Symp. 91.)
 438. Iversen, L. L., C.‐M. Lee, R. F. Gilbert, S. Hunt, and P. C. Emson. Regulation of neuropeptide release. Proc. R. Soc. London B Ser. 210: 91–111, 1980.
 439. Jacob, J. J. C., and K. Ramabadran. Role of opiate receptors and endogenous ligands in nociception. Pharmacol. Ther. 14: 177–196, 1981.
 440. Jacob, J. J. C., E. C. Tremblay, and M. C. Colombel. Facilitation de réaction nociceptives par la naloxone chez la souris et chez le rat. Psychopharmacologia 37: 217–223, 1974.
 441. Jancsó, G., T. Hökfelt, J. M. Lundberg, E. Kiraly, N. Halasz, G. Nilsson, L. Terenius, J. Rehfeld, H. Steinbusch, A. Verhofstad, R. Elde, S. Said, and M. Brown. Immunohistochemical studies of the effect of capsaicin on spinal and medullary peptide and monoamine neurons using antisera to substance P, gastrin/CCK, somatostatin, VIP, enkephalin, neurotensin and 5‐hydroxytryptamine. J. Neurocytol. 10: 963–980, 1981.
 442. Jancsó, N. Desensitization with capsaicin and related acylamides as a tool for studying the function of pain receptors. In: Pharmacology of Pain, edited by R. K. S. Lim. Oxford, UK: Pergamon, 1968, p. 33–55. (Third Int. Pharmacol. Meet.)
 443. Jancsó, N., A. Jancsó‐Gábor, and J. Szolcsányi. Direct evidence for neurogenic inflammation and its prevention by denervation and by pretreatment with capsaicin. Br. J. Pharmacol. 31: 138–151, 1967.
 444. Jancsó, N., and E. Kiraly. Sensory neurotoxins: chemically induced selective destruction of primary sensory neurons. Brain Res. 210: 83–89, 1981.
 445. Jänig, W., and Kollmann, W. The involvement of the sympathetic nervous system in pain. Arzneim. Forsch. 34: 1066–1073, 1984.
 446. Jeftinija, S., V. Miletic, and M. Randic. Cholecystokinin octapeptide excites dorsal horn neurons both in vivo and in vitro. Brain Res. 213: 231–236, 1981.
 447. Jeftinija, S., K. Murase, V. Nedeljkov, and M. Randic. Vasoactive intestinal polypeptide excites mammalian dorsal horn neurons both in vivo and in vitro. Brain Res. 243: 158–164, 1982.
 448. Jeftinija, S., K. Semba, and M. Randic. Norepinephrine reduces excitability of single cutaneous primary afferent C‐fibers in the cat spinal cord. Brain Res. 219: 456–463, 1981.
 449. Jensen, T. S., and T. L. Yaksh. Effects of an intrathecal dopamine agonist, apomorphine, on thermal and chemical evoked noxious responses in rats. Brain Res. 296: 285–293, 1984.
 450. Jensen, T. S., and T. L. Yaksh. Spinal monoamine and opiate systems partly mediate the antinociceptive effects produced by glutamate at brainstem sites. Brain Res. 321: 287–297, 1984.
 451. Jessell, T. M. Substance P in the nervous system. In: Handbook of Psychopharmacology. Biochemical Studies of CNS Receptors, edited by L. L. Iversen and S. H. Snyder. New York: Plenum, 1983, vol. 17, p. 1–105.
 452. Jessell, T. M., and L. L. Iversen. Opiate analgesics inhibit substance P release from rat trigeminal nucleus. Nature London 268: 549–551, 1977.
 453. Jessel, T. M., L. L. Iversen, and A. C. Cuello. Capsaicin‐induced depletion of substance P from primary sensory neurones. Brain Res. 152: 183–188, 1978.
 454. Johannessen, J. N., L. R. Watkins, S. M. Carlton, and D. J. Mayer. Failure of spinal cord serotonin depletion to alter analgesia elicited from the periaqueductal gray. Brain Res. 237: 373–386, 1982.
 455. Johansson, O., T. Hökfelt, B. Pernow, S. L. Jeffcoate, N. White, H. W. M. Steinbusch, A. A. J. Verhofstad, P. C. Emson, and E. Spindel. Immunohistochemical support for three putative transmitters in one neuron. Neuroscience 6: 1857–1881, 1981.
 456. Jones, D. J., D. E. Kendal, and S. J. Enna. Adrenergic receptors in rat spinal cord. Life Sci. 24: 191–196, 1982.
 457. Jones, E. G. Thalamic basis for column‐like input to monkey somatic sensory and motor cortex. In: Somatosensory Integration in the Thalamus: A Reevaluation Based on the New Methodological Approaches, edited by G. Macchi, A. Rustioni, and R. Spreafico. Amsterdam: Elsevier, 1983, p. 309–336.
 458. Jordan, L. M., D. R. Kenshalo, Jr., R. F. Martin, L. H. Haber, and W. D. Willis. Depression of primate spinothalamic tract neurons by iontophoretic application of 5‐hydroxytryptamine. Pain 5: 135–142, 1978.
 459. Jordan, L. M., D. R. Kenshalo, Jr., R. F. Martin, L. H. Haber, and W. D. Willis. Two populations of spinothalamic tract neurons with opposite responses to 5‐hydroxytryptamine. Brain Res. 164: 342–346, 1979.
 460. Juan, H. Prostaglandins as modulators of pain. Gen. Pharmacol. 9: 403–409, 1978.
 461. Jurna, I. Inhibition of the effect of repetitive stimulation on spinal motoneurones of the cat by morphine and pethidine. Int. J. Neuropharmacol. 5: 117–123, 1966.
 462. Jurna, I. Effect of stimulation in the periaqueductal grey matter on activity in ascending axons of the rat spinal cord: selective inhibition of activity evoked by afferent A‐delta and C‐fibre stimulation and failure of naloxone to reduce inhibition. Brain Res. 196: 33–42, 1980.
 463. Jurna, I., W. Grossman, and C. Theres. Inhibition by morphine of repetitive activations of cat spinal motoneurones. Neuropharmacology 12: 983–993, 1973.
 464. Jurna, I., and G. Heinz. Differential effects of morphine and opioid analgesics on A and C fibre evoked activity in ascending axons of the rat spinal cord. Brain Res. 171: 573–576, 1979.
 465. Jurna, I., G. Heinz, G. Blinn, and T. Nell. The effect of substantia nigra stimulation and morphine on alpha‐motoneurons and the tail flick response. Eur. J. Pharmacol. 51: 239–250, 1978.
 466. Jurna, I., W. R. Schlue, and U. Tamm. The effect of morphine on primary somatosensory evoked responses in the rat cerebral cortex. Neuropharmacology 11: 409–415, 1972.
 467. Jurna, I., and G. Zetler. Antinociceptive effect of centrally administered caerulein and cholecystokinin octapeptide (CCK‐8). Eur. J. Pharmacol. 73: 323–331, 1981.
 468. Kaada, B. Neurophysiology and acupuncture: a review. In: Advances in Pain Research and Therapy. Proceeding of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976, vol. 1, p. 733–741.
 469. Kalivas, P. W., B. A. Gan, C. B. Nemeroff, and A. J. Prange, Jr. Antinociception after microinjection of neurotensin into the central amygdaloid nucleus of the rat. Brain Res. 243: 279–286, 1982.
 470. Kalivas, P. W., L. Jennes, C. B. Nemeroff, and A. J. Prange, Jr. Neurotensin. Topographical distribution of brain sites involved in hypothermia and antinociception. J. Comp. Neurol. 210: 225–238, 1982.
 471. Kane, K., and A. Taub. A history of local electrical analgesia. Pain 1: 125–138, 1975.
 472. Kelly, J. S. Electrophysiology of peptides in the central nervous system. Br. Med. Bull. 38: 283–290, 1982.
 473. Kenins, P. Responses of single nerve fibers to capsaicin applied to the skin. Neurosci. Lett. 42: 311–316, 1982.
 474. Kenshalo, D. R., Jr., G. J. Giesler, Jr., R. B. Leonard, and W. D. Willis. Responses of neurons in primate ventral posterior lateral nucleus to noxious stimuli. J. Neurophysiol. 43: 1594–1614, 1980.
 475. Kenshalo, D. R., Jr., and O. Isensee. Effects of noxious stimuli on primate SI cortical neurons. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 139–154.
 476. Kenshalo, D. R., Jr., and O. Isensee. Responses of primate SI cortical neurons to noxious stimuli. J. Neurophysiol. 50: 1479–1496, 1983.
 477. Kenshalo, D. R., Jr., R. B. Leonard, J. M. Chung, and W. D. Willis. Responses of primate spinothalamic neurons to graded and to repeated noxious heat stimuli. J. Neurophysiol. 42: 1370–1389, 1979.
 478. Kerr, F. W. L. Neuroanatomical substrates of nociception in the spinal cord. Pain 1: 325–356, 1975.
 479. Kerr, F. W. L., and T. F. Fukushima. New observations on the nociceptive pathways in the central nervous system. In: Pain, edited by J. J. Bonica. New York: Raven, 1980, p. 47–61.
 480. Kerr, F. W. L., P. R. Wilson, and D. E. Nijensohn. Acupuncture reduces the trigeminal evoked response in decerebrate cats. Exp. Neurol. 61: 84–95, 1978.
 481. Kevetter, G. A., and W. D. Willis. Spinothalamic cells in the rat lumbar cord with collaterals to the medullary reticular formation. Brain Res. 238: 181–185, 1982.
 482. Kneisley, L. W., M. P. Biber, and J. H. La Vail. A study of the origin of brain stem projections to monkey spinal cord using the retrograde transport method. Exp. Neurol. 60: 116–139, 1978.
 483. Kniffki, K. D., S. Mense, and R. F. Schmidt. The spinocervical tract as a possible pathway for muscular nociception. J. Physiol. Paris 73: 359–366, 1977.
 484. Kniffki, K.‐D., and K. Mizumura. Responses of neurons in VPL and VPL‐VL region of the cat to algesic stimulation of muscle and tendon. J. Neurophysiol. 49: 649–661, 1983.
 485. Knyihar, E. Fluoride‐resistant and phosphatase system of nociceptive dorsal root afferents. Experientia 27: 1205–1207, 1971.
 486. Knyihar‐Csillik, E., B. Csillik, and P. Rakic. Periterminal synaptology of dorsal root glomerular terminals in the substantia gelatinosa of the spinal cord in the rhesus monkey. J. Comp. Neurol. 210: 376–399, 1982.
 487. Komisaruk, B. R., B. Ciofalo, and M. B. Latranyi. Stimulation of the vaginal cervix is more effective than morphine in suppressing a nociceptive response in rats. In: Advances in Pain Research and Therapy. Proceedings of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976, vol. 1, p. 439–443.
 488. Komisaruk, B. R., and J. Wallman. Antinociceptive effects of vaginal stimulation in rats: neurophysiological and behavioural studies. Brain Res. 137: 85–107, 1977.
 489. Korf, J., B. Bunney, and G. Aghajanian. Noradrenergic neurons: morphine inhibition of spontaneous activity. Eur. J. Pharmacol. 25: 165–169, 1974.
 490. Krivoy, W., and R. A. Huggins. The action of morphine, methadone, meperidine, and nalorphine on dorsal root potentials of cat spinal cord. J. Pharmacol. Exp. Ther. 134: 210–213, 1961.
 491. Kumazawa, T., and K. Mizumura. The polymodal C‐fiber receptor in the muscle of the dog. Brain Res. 101: 589–593, 1976.
 492. Kumazawa, T., and K. Mizumura. Thin‐fibre receptors responding to mechanical, chemical and thermal stimulation in the skeletal muscle of the dog. J. Physiol. London 273: 179–194, 1977.
 493. Kumazawa, T., and E. R. Perl. Differential excitation of dorsal horn and substantia gelatinosa marginal neurons by primary afferent units with fine (A delta and C) fibers. In: Sensory Functions of the Skin in Primates, With Special Reference to Man, edited by Y. Zotterman. New York: Pergamon, 1977, p. 67–88.
 494. Kumazawa, T., and E. R. Perl. Excitation of marginal and substantia gelatinosa neurons in the primate spinal cord: indication of their place in dorsal horn functional organization. J. Comp. Neurol. 177: 417–434, 1978.
 495. Kuraishi, Y., Y. Harada, M. Satoh, and H. Takagi. Antagonism by phenoxybenzamine of the analgesic effect of morphine injected into the n. reticulogigantocellularis of the rat. Neuropharmacology 18: 107–110, 1979.
 496. Kuypers, H. G. J. M., and A. M. Huisman. The new anatomy of the descending brain pathways. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 29–54.
 497. Kuypers, H. G. J. M., and V. A. Maisky. Retrograde axonal transport of horseradish peroxidase from spinal cord to brain stem cell groups in the cat. Neurosci. Lett. 1: 9–14, 1975.
 498. Kuypers, H. G. J. M., and V. A. Maisky. Funicular trajectories of descending brain stem pathways in cat. Brain Res. 136: 159–165, 1977.
 499. Lal, H., T. Spaulding, and S. Fielding. Swim‐stress induced analgesia and lack of its naloxone antagonism. Commun. Psychopharmacol. 2: 263–266, 1978.
 500. La Motte, C. Distribution of the tract of Lissauer and the dorsal root fibers in the primate spinal cord. J. Comp. Neurol. 172: 529–562, 1977.
 501. La Motte, C. C., and N. C. de Lanerolle. Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. II. Methionine‐enkephalin immunoreactivity. Brain Res. 274: 51–63, 1983.
 502. La Motte, C., C. B. Pert, and S. H. Snyder. Opiate receptor binding in primate spinal cord: distribution and changes after dorsal root section. Brain Res. 112: 407–412, 1976.
 503. La Motte, R. H., and J. N. Campbell. Comparison of responses of warm and nociceptive C‐fiber afferents in monkey with human judgements of thermal pain. J. Neurophysiol. 41: 509–528, 1978.
 504. Lamour, Y., G. Guilbaud, and J. C. Willer. Rat somatosensory SmI cortex. I. Characteristics of neuronal responses to noxious stimulation and comparison with responses to non‐noxious stimulation. Exp. Brain Res. 49: 39–45, 1983.
 505. Lamour, Y., G. Guilbaud, and J. C. Willer. Rat somatosensory SmI cortex. II. Laminar and columnar organization of noxious and non‐noxious inputs. Exp. Brain Res. 49: 46–54, 1983.
 506. Lamour, Y., J. C. Willer, and G. Guilbaud. Neuronal responses to noxious stimulation in rat somatosensory cortex. Neurosci. Lett. 29: 35–40, 1982.
 507. Langford, L. A., and R. E. Coggeshall. Branching of sensory axons in the peripheral nerve of the rat. J. Comp. Neurol. 203: 745–750, 1981.
 508. Larsen, J. J., and A. V. Christensen. Subarachnoidal administration of the 5‐HT uptake inhibitor citalopram points to the spinal role of 5‐HT in morphine antinociception. Pain 14: 339–345, 1982.
 509. Leander, S., R. Håkanson, S. Rosell, K. Folkers, F. Sundler, and K. Tornquist. A specific substance P antagonist blocks smooth muscle contractions induced by non‐cholinergic, non‐adrenergic nerve stimulation. Nature London 294: 467–469, 1981.
 510. Le Bars, D., and D. Chitour. Do convergent neurones in the spinal dorsal horn discriminate nociceptive from non‐nociceptive information? Pain 17: 1–19, 1983.
 511. Le Bars, D., D. Chitour, E. Kraus, A. M. Clot, A. H. Dickenson, and J. M. Besson. The effect of systemic morphine upon diffuse noxious inhibitory controls (DNIC) in the rat: evidence for a lifting of certain descending inhibitory controls of dorsal horn convergent neurones. Brain Res. 215: 257–274, 1981.
 512. Le Bars, D., A. H. Dickenson, and J. M. Besson. Diffuse noxious inhibitory controls (DNIC). I. Effects on dorsal horn convergent neurones in the rat. Pain 6: 283–304, 1979.
 513. Le Bars, D., A. H. Dickenson, and J. M. Besson. Diffuse noxious inhibitory controls (DNIC). II. Lack of effect on non‐convergent neurones, supraspinal involvement and theoretical implications. Pain 6: 305–327, 1979.
 514. Le Bars, D., A. H. Dickenson, and J. M. Besson. Microinjection of morphine within nucleus raphe magnus and dorsal horn neurone activities related to nociception in the rat. Brain Res. 189: 467–481, 1980.
 515. Le Bars, D., A. H. Dickenson, and J. M. Besson. The triggering of bulbo‐spinal serotonergic inhibitory controls by noxious peripheral inputs. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 381–410.
 516. Le Bars, D., A. H. Dickenson, and J. M. Besson. Opiate analgesia and descending control systems. In: Advances in Pain Research and Therapy, Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 341–372.
 517. Le Bars, D., G. Guilbaud, D. Chitour, and J. M. Besson. Does systemic morphine increase descending inhibitory controls of dorsal horn neurones involved in nociception? Brain Res. 202: 223–228, 1980.
 518. Le Bars, D., G. Guilbaud, I. Jurna, and J. M. Besson. Differential effects of morphine on responses of dorsal horn lamina V type cells elicited by A and C fibre stimulation in the spinal cat. Brain Res. 115: 518–524, 1976.
 519. Le Bars, D., D. Menetrey, and J. M. Besson. Effects of morphine upon the lamina V type cell activities in the dorsal horn of the decerebrate cat. Brain Res. 113: 293–310, 1976.
 520. Lee, C. M. Enzymatic inactivation of substance P in the central nervous system. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 165–185. (Ciba Found. Symp. 91.)
 521. Lembeck, F., K. Folkers, and J. Donnerer. Analgesic effect of antagonists of substance P. Biochem. Biophys. Res. Commun. 103: 1318–1321, 1981.
 522. Lembeck, F., and R. Gamse. Substance P in peripheral sensory processes. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 35–54. (Ciba Found. Symp. 91.)
 523. Levine, J. D., N. C. Gordon, and H. L. Fields. The mechanism of placebo analgesia. Lancet 2: 654–657, 1978.
 524. Levine, J. D., N. C. Gordon, R. T. Jones, and H. L. Fields. The narcotic antagonist naloxone enhances clinical pain. Nature London 272: 826–827, 1978.
 525. Levine, J. D., S. R. Lane, N. C. Gordon, and H. L. Fields. A spinal opioid synapse mediates the interaction of spinal and brain stem sites in morphine analgesia. Brain Res. 236: 85–91, 1982.
 526. Levy, R. A., and H. K. Proudfit. The analgesic action of baclofen [beta‐(4‐chlorophenol)‐gamma‐aminobutyric acid]. J. Pharmacol. Exp. Ther. 202: 437–445, 1977.
 527. Levy, R. A., and H. K. Proudfit. Analgesia produced by microinjection of baclofen and morphine at brain stem sites. Eur. J. Pharmacol. 57: 43–55, 1979.
 528. Lewis, J. W., J. T. Cannon, and J. C. Liebeskind. Opioid and non‐opioid mechanisms of stress analgesia. Science 208: 623–625, 1980.
 529. Lewis, J. W., G. W. Terman, Y. Shavit, L. R. Nelson, and J. C. Liebeskind. Neural, neurochemical, and hormonal bases of stress‐induced analgesia. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 277–288.
 530. Lewis, J. W., G. W. Terman, L. R. Watkins, D. J. Mayer, and J. C. Liebeskind. Opioid and nonopioid mechanisms of footshock‐induced analgesia: role of the spinal dorsolateral funiculus. Brain Res. 267: 139–144, 1983.
 531. Lewis, J. W., M. G. Tordoff, J. E. Sherman, and J. C. Liebeskind. Adrenal medullary enkephalin‐like peptides may mediate opioid stress analgesia. Science 217: 557–559, 1982.
 532. Lewis, V. A., and G. F. Gebhart. Evaluation of the periaqueductal central gray (PAG) as a morphine‐specific locus of action and examination of morphine‐induced and stimulation‐produced analgesia at coincident PAG loci. Brain Res. 124: 283–303, 1977.
 533. Lewis, V. A., and G. F. Gebhart. Morphine‐induced and stimulation‐produced analgesia at coincident periaquaeductal central gray loci: evaluation of analgesic congruence, tolerance and cross‐tolerance. Exp. Neurol. 57: 934–955, 1977.
 534. Li, C. L. Neurological basis of pain and its possible relationship to acupuncture‐analgesia. Am. J. Chin. Med. 1: 61–72, 1973.
 535. Liebeskind, J. C., G. Guilbaud, J. M. Besson, and J. L. Oliveras. Analgesia from electrical stimulation of the periaquaeductal gray matter in the cat: behavioral observations and inhibitory effects on spinal cord interneurons. Brain Res. 50: 441–446, 1973.
 536. Light, A. R., and E. R. Perl. Differential termination of large‐diameter and small‐diameter primary afferent fibers in the spinal dorsal gray matter as indicated by labelling with horseradish peroxidase. Neurosci. Lett. 6: 59–63, 1977.
 537. Light, A. R., D. L. Trevino, and E. R. Perl. Morphological features of functionally defined neurons in the marginal zone and substantia gelatinosa of the spinal dorsal horn. J. Comp. Neurol. 186: 151–172, 1979.
 538. Lim, R. K. S. Pain. Annu. Rev. Physiol. 32: 269–288, 1970.
 539. Lin, R. P. C. Laminar origins of spinal projection neurons to periaqueductal gray of the rat. Brain Res. 264: 118–122, 1983.
 540. Loeser, J. D. Definition, etiology and neurological assessment of pain originating in the nervous system following deafferentiation. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 701–711.
 541. Loh, Y. P., M. L. Brownstein, and H. Gainer. Proteolysis in neuropeptide processing and other neural functions. Annu. Rev. Neurosci. 7: 189–222, 1984.
 542. Long, J. B., P. W. Kalivas, W. W. Youngblood, A. J. Prange, Jr., and J. S. Kizer. Possible involvement of serotonergic neurotransmission in neurotensin but not in morphine analgesia. Brain Res. 310: 35–41, 1984.
 543. Lovick, T. A., D. C. West, and J. H. Wolstencroft. Interactions between brain stem raphe nuclei and the trigeminal nuclei. In: Pain in the Trigeminal Region, edited by D. J. Anderson and B. Matthews. Amsterdam: Elsevier/North‐Holland, 1977, p. 307–317.
 544. Lu, G.‐D., and J. Needham. Celestial Lancets. A History and Rationale of Acupuncture and Moxa. Cambridge, UK: Cambridge Univ. Press, 1980.
 545. Lu, G. W., G. J. Bennett, N. Nishikawa, M. J. Hoffert, and R. Dubner. Extra‐ and intracellular recordings from dorsal column postsynaptic spinomedullary neurons in the cat. Exp. Neurol. 82: 456–477, 1983.
 546. Lundberg, A. Inhibitory control from the brain stem of transmission from primary afferents to motoneurons, primary afferent terminals and ascending pathways. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 179–224.
 547. Luttinger, D. Peptides and nociception. In: International Review of Neurobiology, edited by J. R. Smythies and R. J. Bradley. New York: Academic, 1984, vol. 25, p. 185–241.
 548. Lynn, B., and E. R. Perl. Failure of acupuncture to produce localized analgesia. Pain 3: 339–351, 1977.
 549. Madden, J., H. Akil, R. L. Patrick, and J. D. Barchas. Stress‐induced parallel changes in central opioid levels and pain responsiveness in the rat. Nature London 265: 358–360, 1977.
 550. Maier, S. F., R. C. Drugan, and J. W. Grau. Controllability, coping behavior, and stress‐induced analgesia in the rat. Pain 12: 47–56, 1982.
 551. Malick, J. B., and J. M. Goldstein. Analgesic activity of substance P following intracerebral administration in rats. Life Sci. 23: 835–844, 1978.
 552. Mann, F. Acupuncture analgesia: report of 100 experiments. Br. J. Anaesth. 46: 361–364, 1974.
 553. Mantyh, P. W. Forebrain projections to the periaqueductal grey in the monkey with observations in the cat and rat. J. Comp. Neurol. 204: 349–363, 1982.
 554. Margalit, D., and M. Segal. A pharmacologic study of analgesia produced by stimulation of the nucleus locus coeruleus. Psychopharmacology 62: 169–173, 1979.
 555. Marshall, K. C. Catecholamines and their actions in the spinal cord. In: Handbook of the Spinal Cord. Pharmacology, edited by R. A. Davidoff. New York: Dekker, 1983, vol. 1, p. 275–328.
 556. Marshall, K. C., R. Y. K. Pun, W. J. Hendelman, and P. G. Nelson. A coeruleo‐spinal system in culture. Science 213: 355–357, 1981.
 557. Martin, G. F., A. O. Humbertson, Jr., C. Laxson, and W. M. Panneton. Dorsolateral ponto‐spinal systems. Possible routes for catecholamine modulation of nociception. Brain Res. 163: 333–338, 1979.
 558. Mayer, D. J., and R. Hayes. Stimulation‐produced analgesia: development of tolerance and cross‐tolerance to morphine. Science 188: 941–943, 1975.
 559. Mayer, D. J., and J. C. Liebeskind. Pain reduction by focal electrical stimulation of the brain: an anatomical and behavioural analysis. Brain Res. 68: 73–93, 1974.
 560. Mayer, D. J., and D. D. Price. Central nervous system mechanisms of analgesia. Pain 2: 379–404, 1976.
 561. Mayer, D. J., D. D. Price, and D. P. Becker. Neurophysiological characterization of the anteriolateral spinal cord neurons contributing to pain perception in man. Pain 1: 51–58, 1975.
 562. Mayer, D. J., D. D. Price, and A. Rafii. Antagonism of acupuncture analgesia in man by the narcotic antagonist naloxone. Brain Res. 121: 368–372, 1977.
 563. Mayer, D. J., and L. R. Watkins. Role of endorphins in endogenous pain control systems. In: Modern Problems of Pharmacopsychiatry. The Role of Endorphins in Neuropsychiatry, edited by H. M. Emrich. Basel: Karger, 1981, p. 68–96.
 564. Mayer, D. J., and L. R. Watkins. Multiple endogenous opiate and nonopiate analgesia systems. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 253–276.
 565. Mayer, D. J., T. L. Wolfle, H. Akil, B. Carder, and J. C. Liebeskind. Analgesia from electrical stimulation in the brain stem of the rat. Science 174: 1351–1354, 1971.
 566. Mayer, M. L., and R. G. Hill. The effect of intravenous fentanyl, morphine, and naloxone on nociceptive responses of neurones in the rat caudal medulla. Neuropharmacology 17: 533–539, 1977.
 567. Mazars, G. L., L. Merienne, and C. Cioloca. Comparative study of electrical stimulation of posterior thalamic nuclei, periaquaeductal gray, and other midline mesencephalic structures in man. In: Advances in Pain Research and Therapy. Proceedings of the Second World Congress on Pain, edited by J. J. Bonica, J. C. Liebeskind, and D. G. Albe‐Fessard. New York: Raven, 1979, vol. 3, p. 541–546.
 568. McCarthy, P. S., R. J. Walker, M. Yajima, K. Kitagawa, and G. N. Woodruff. The action of neurotensin on neurons in the nucleus accumbens and cerebellum of the rat. Gen. Pharmacol. 10: 331–333, 1979.
 569. McCreery, D. B., and J. R. Bloedel. Reduction of the response of cat spinothalamic neurons to graded mechanical stimuli by electrical stimulation of the lower brain stem. Brain Res. 97: 151–156, 1975.
 570. McCreery, D. B., and J. R. Bloedel. Effect of trigeminal stimulation on the excitability of cat spinothalamic neurons. Brain Res. 117: 136–140, 1976.
 571. McCreery, D. B., J. R. Bloedel, and E. G. Hames. Effects of stimulating in raphe nuclei and in reticular formation on response of spinothalamic neurons to mechanical stimuli. J. Neurophysiol. 42: 166–182, 1979.
 572. McGinty, J. F., S. J. Henriksen, A. Goldstein, L. Terenius, and F. E. Bloom. Dynorphin is contained within hippocampal mossy fibers: immunochemical alterations after kainic acid administration and colchicine‐induced neurotoxicity. Proc. Natl. Acad. Sci. USA 80: 589–593, 1983.
 573. McGinty, J. F., D. van der Kooy, and F. E. Bloom. The distribution and morphology of opioid peptide immunoreactive neurons in the cerebral cortex of rats. J. Neurosci. 4: 1104–1117, 1984.
 574. McLaughlin, B. J., R. Barber, K. Saito, E. Roberts, and J. Y. Wu. Immunocytochemical localization of glutamate decarboxylase in rat spinal cord. J. Comp. Neurol. 164: 305–322, 1975.
 575. McLennan, H., K. Gilfillan, and Y. Heap. Some pharmacological observations on the analgesia induced by acupuncture in rabbits. Pain 3: 229–238, 1977.
 576. McMahon, S. B., and P. D. Wall. A system of rat spinal cord lamina I cells projecting through the contralateral dorsolateral funiculus. J. Comp. Neurol. 214: 217–223, 1983.
 577. Melzack, R. The McGill pain questionnaire: major properties and scoring methods. Pain 1: 277–299, 1975.
 578. Melzack, R. Pain Measurement and Assessment. New York: Raven, 1983.
 579. Melzack, R. Neuropsychological basis of pain measurement. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 323–340.
 580. Melzack, R., and D. F. Melinkoff. Analgesia produced by brain stimulation: evidence of a prolonged onset period. Exp. Neurol. 43: 369–379, 1974.
 581. Melzack, R., and P. D. Wall. Pain mechanisms: a new theory. Science 150: 971–978, 1965.
 582. Mendell, L. M. Physiological properties of unmyelinated fiber projections to the spinal cord. Exp. Neurol. 16: 316–332, 1966.
 583. Menétrey, D., A. Chaouch, and J. M. Besson. Location and properties of dorsal horn neurons at origin of spinoreticular tract in lumbar enlargement of the rat. J. Neurophysiol. 44: 862–877, 1980.
 584. Menétrey, D., A. Chaouch, D. Binder, and J. M. Besson. The origin of the spinomesencephalic tract in the rat: an anatomical study using the retrograde transport of horseradish peroxidase. J. Comp. Neurol. 206: 193–207, 1982.
 585. Mense, S. Sensitization of group IV muscle receptors to bradykinin by 5‐hydroxytryptamine and prostaglandin E2. Brain Res. 225: 95–105, 1981.
 586. Mense, S., and M. Stahnke. Responses in muscle afferent fibres of slow conduction velocity to contractions and ischaemia in the cat. J. Physiol. Lond. 342: 383–397, 1983.
 587. Messing, R. B., C. Flinchbaugh, and J. C. Waymire. Tryptophan and 5‐hydroxyindoles in different CNS regions following acute morphine. Eur. J. Pharmacol. 48: 137–140, 1978.
 588. Messing, R. B., and L. D. Lytle. Serotonin‐containing neurons: their possible role in pain and analgesia. Pain 4: 1–22, 1977.
 589. Metys, J., N. Wagner, J. Metysova, and A. Herz. Studies on the central antinociceptive action of cholinomimetic agents. Int. J. Neuropharmacol. 8: 413–425, 1969.
 590. Meyerson, B. A. Electrostimulation procedures: effects, presumed rationale, and possible mechanisms. In: Advances in Pain Research and Therapy, Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 495–534.
 591. Miletic, V., and M. Randic. Neurotensin excites cat spinal neurons located in lamina I‐III. Brain Res. 169: 600–604, 1979.
 592. Millan, M. J. Stress and endogenous opioid peptides: a review. In: Modern Problems of Pharmacopsychiatry. The Role of Endorphins in Neuropsychiatry, edited by H. M. Emrich. Basel: Karger, 1981, p. 49–67.
 593. Millan, M. J., R. Przewlocki, and A. Herz. A non‐beta‐endorphinergic adenohypophyseal mechanism is essential for an algetic response to stress. Pain 8: 343–353, 1980.
 594. Millan, M. J., R. Przewlocki, M. Jerlitz, C. Gramsch, V. Höllt, and A. Herz. Stress‐induced release of brain and pituitary beta‐endorphin: major role in generation of hyperthermia, not analgesia. Brain Res. 208: 325–338, 1981.
 595. Millar, J., and M. Armstrong‐James. The responses of neurones of the superficial dorsal horn to iontophoretically applied glutamate ion. Brain Res. 231: 267–277, 1982.
 596. Milne, R. J., R. D. Foreman, G. J. Giesler, and W. D. Willis. Convergence of cutaneous and pelvic visceral nociceptive inputs onto primate spinothalamic neurons. Pain 11: 163–183, 1981.
 597. Milne, R. J., R. D. Foreman, G. L. Giesler, Jr., and W. D. Willis. Viscerosomatic convergence onto primate spinothalamic neurons: an explanation for referral of pelvic visceral pain. In: Advances in Pain Research and Therapy, Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 131–137.
 598. Mitchell, D., and R. F. Hellon. Neuronal and behavioral responses in rats during noxious stimulation of the tail. Proc. R. Soc. London. 197: 169–194, 1977.
 599. Mohrland, J. S., and G. F. Gebhart. Substance P‐induced analgesia in the rat. Brain Res. 171: 556–559, 1979.
 600. Mohrland, J. S., and G. F. Gebhart. Effects of focal electrical stimulation and morphine microinjection in the periaquaeductal gray of the rat mesencephalon and neuronal activity in the medullary reticular formation. Brain Res. 201: 23–37, 1980.
 601. Molenaar, G. M., J. A. Holloway, and C. O. Trouth. Responses of caudal raphe neurons to peripheral somatic stimulation. Exp. Neurol. 53: 304–313, 1976.
 602. Molony, V., W. M. Steedman, F. Cervero, and A. Iggo. Intracellular marking of identified neurones in the superficial dorsal horn of the cat spinal cord. Q. J. Exp. Physiol. 66: 211–223, 1981.
 603. Moncada, S., S. H. Ferreira, and J. R. Vane. Inhibition of prostaglandin synthesis as the mechanism of analgesia of aspirin‐like drugs in the dog knee joint. Eur. J. Pharmacol. 31: 250–260, 1975.
 604. Moody, T. W., T. L. O'Donohue, and D. M. Jacobowitz. Biochemical localisation and characterisation of bombesin‐like peptides in discrete regions of rat brain. Peptides 2: 75–79, 1981.
 605. Moody, T. W., N. B. Thoa, T. L. O'Donohue, and D. M. Jacobowitz. Bombesin‐like peptides in rat spinal cord: biochemical characterisation, localisation and mechanism of release. Life Sci. 29: 2273–2279, 1981.
 606. Moore, R. Y. Anatomy of central serotonin neuron systems in the rat brain. In: Serotonin, Neurotransmission and Behavior, edited by B. L. Jacobs and A. Gelperin. Cambridge, MA: MIT Press, 1981, p. 35–71.
 607. Moore, R. Y., and F. E. Bloom. Central catecholamine neuron system: anatomy and physiology of the dopamine systems. Annu. Rev. Neurosci. 1: 129–169, 1978.
 608. Moore, R. Y., and F. E. Bloom. Central catecholamine neuron systems: anatomy and physiology of the norepinephrine and epinephrine systems. Annu. Rev. Neurosci. 22: 113–168, 1979.
 609. Moricca, G. Neuroadenolysis (chemical hypophysectomy) for diffuse unbearable cancer pain. In: Advances in Pain Research and Therapy. Proceedings of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976, vol. 1, p. 863–866.
 610. Morton, C. R., A. W. Duggan, and Z. Q. Zhao. The effects of lesions of medullary midline and lateral reticular areas on inhibition in the dorsal horn produced by periaqueductal gray stimulation in the cat. Brain Res. 301: 121–130, 1984.
 611. Moss, M. S., E. J. Glazer, and A. I. Basbaum. The peptidergic organization of the cat periaqueductal gray. I. Distribution of immunoreactive enkephalin‐containing neurons and terminals. Neuroscience 3: 603–616, 1983.
 612. Mosso, J. A., and L. Kruger. Spinal trigeminal neurons excited by noxious and thermal stimuli. Brain Res. 38: 206–210, 1972.
 613. Mouchet, P., B. Guerin, and C. Feuerstein. Dissociate destruction of noradrenaline and dopamine descending projections in the thoracic spinal cord of the rat. Life Sci. 30: 373–381, 1982.
 614. Mountcastle, V. B., G. F. Poggio, and G. Werner. The relation of thalamic cell response to peripheral stimuli varied over an intensive continuum. J. Neurophysiol. 26: 807–834, 1963.
 615. Mountcastle, V. B., and T. P. S. Powell. Neural mechanisms subserving cutaneous sensibility, with special reference to the role of afferent inhibition in sensory perception and discrimination. Bull. Johns Hopkins Hosp. 105: 201–232, 1959.
 616. Moyano, R. S., D. Kayser, Y. Grall, A. Hernandez, S. Ruiz, and C. Paeile. Effect of pentazocine on the evoked potentials recorded in the primary somesthetic cortical areas of guinea pigs. Brain Res. 88: 475–481, 1975.
 617. Mudge, A. W., S. E. Leemann, and G. D. Fischbach. Enkephalin inhibits release of substance P from sensory neurons in culture and decreases action potential duration. Proc. Natl. Acad. Sci. USA 76: 526–530, 1979.
 618. Murase, K., V. Nedeljkov, and M. Randic. The actions of neuropeptides on dorsal horn neurons in the rat spinal cord slice preparation: an intracellular study. Brain Res. 234: 170–176, 1982.
 619. Nagy, J. I., and S. P. Hunt. The termination of primary afferents within the rat dorsal horn: evidence for rearrangement following capsaicin treatment. J. Comp. Neurol. 218: 145–158, 1983.
 620. Nagy, J. I., S. R. Vincent, W. A. Staines, H. C. Fibiger, T. D. Reisine, and H. I. Yamamura. Neurotoxic action of capsaicin on spinal substance P neurons. Brain Res. 186: 435–444, 1980.
 621. Nahin, R. L., A. M. Madsen, and G. J. Giesler. Anatomical and physiological studies of the gray matter surrounding the spinal cord central canal. J. Comp. Neurol. 220: 321–335, 1983.
 622. Nathan, P. W. The gate‐control theory of pain: a critical review. Brain 99: 123–158, 1976.
 623. Nathan, P. W. Involvement of the sympathetic nervous system in pain. In: Pain and Society, edited by H. W. Kosterlitz and L. Y. Terenius. Weinheim, West Germany: Chemie, 1980, p. 324–331.
 624. Neale, J. H., and J. L. Barker. Peptides: diverse elements in spinal‐sensory function. In: Handbook of the Spinal Cord. Pharmacology, edited by R. A. Davidoff. New York: Dekker, 1983, vol. 1, p. 171–202.
 625. Nemeroff, C. B., and A. J. Prange, Jr. Neurotensin: A Brain and Gastrointestinal Peptide, edited by C. B. Nemeroff and A. J. Prange, Jr., New York: NY Acad. Sci., 1982.
 626. Nemeroff, C. B., D. Luttinger, and A. J. Prange Jr. Neurotensin and bombesin. In: Handbook of Psychopharmacology. Neuropeptides, edited by S. D. Iversen and S. H. Snyder. New York: Plenum, 1983, vol. 16, p. 363–466.
 627. Newberry, N. R., and R. A. Nicoll. Comparison of the action of baclofen with gamma‐aminobutyric acid on rat hippocampal cells in vitro. J. Physiol. London 360: 161–185, 1985.
 628. Nicoll, R. A., B. E. Alger, and C. E. Jahr. Enkephalin blocks inhibitory pathways in the vertebrate CNS. Nature London 287: 22–25, 1980.
 629. Nicoll, R. A., C. Schenker, and S. F. Leeman. Substance P as a transmitter candidate. Annu. Rev. Neurosci. 3: 227–268, 1980.
 630. Ninkovic, M., S. P. Hunt, and J. R. W. Gleave. Localization of opiate and histamine H1‐receptors in the primate sensory ganglia and spinal cord. Brain Res. 241: 197–206, 1982.
 631. Nistri, A. Spinal cord pharmacology of GABA and chemically related amino acids. In: Handbook of the Spinal Cord. Pharmacology, edited by R. A. Davidoff. New York: Dekker, 1983, vol. 1, p. 45–104.
 632. Nistri, A. A., and A. Constanti. Pharmacological characterisation of different types of GABA and glutamate receptors in vertebrates and invertebrates. Prog. Neurobiol. 13: 117–235, 1979.
 633. North, R. A. Opiates, opioid peptides and single neurones. Life Sci. 24: 1527–1546, 1979.
 634. North, R. A., Y. Katayama, and J. T. Williams. On the mechanism and site of action of enkephalin on single myenteric neurones. Brain Res. 165: 67–77, 1979.
 635. North, R. A., and M. Yoshimura. The actions of noradrenaline on neurones of the rat substantia gelatinosa in vitro. J. Physiol. London 349: 43–55, 1984.
 636. Nowak, L. M., and R. L. Macdonald. Substance P decreases a potassium conductance of spinal cord neurons in cell culture. Brain Res. 214: 416–423, 1981.
 637. Nowak, L. M., and R. L. Macdonald. Substance P: ionic basis for depolarizing responses of mouse spinal cord neurons in cell culture. J. Neurosci. 2: 1119–1128, 1982.
 638. Nyberg‐Hansen, R. Sites and mode of termination of reticulospinal fibers in the cat. An experimental study with silver impregnation methods. J. Comp. Neurol. 124: 71–100, 1965.
 639. Nygren, L., and L. Olson. A new major projection from locus coeruleus: the main source of noradrenergic nerve terminals in the ventral and dorsal columns of the spinal cord. Brain Res. 132: 85–93, 1977.
 640. O'Connor, J., and D. Benskey. A summary of research concerning the effects of acupuncture. Am. J. Chin. Med. 3: 377–394, 1975.
 641. Oleson, T. D., D. B. Kirkpatrick, and S. J. Goodman. Elevation of pain threshold to tooth shock by brain stimulation in primates. Brain Res. 194: 79–95, 1980.
 642. Oleson, T. D., D. A. Twombly, and J. C. Liebeskind. Effects of pain‐attenuating brain stimulation and morphine on electrical activity in the raphe nuclei of the awake rat. Pain 4: 211–230, 1978.
 643. Oliveras, J. L., J. M. Besson, G. Guilbaud, and J. C. Liebeskind. Behavioural and electrophysiological evidence of pain inhibition from midbrain stimulation in the cat. Exp. Brain Res. 20: 32–44, 1974.
 644. Oliveras, J. L., Y. Hosobuchi, G. Guilbaud, and J. M. Besson. Analgesia electrical stimulation of the feline nucleus raphe magnus: development of tolerance and its reversal by 5‐HTP. Brain Res. 146: 404–409, 1978.
 645. Oliveras, J. L., Y. Hosobuchi, F. Redjemi, G. Guilbaud, and J. M. Besson. Opiate antagonist, naloxone, strongly reduces analgesia induced by stimulation of a raphe nucleus (centralis inferior). Brain Res. 120: 221–229, 1977.
 646. Oliveras, J. L., F. Redjemi, G. Guilbaud, and J. M. Besson. Analgesia induced by electrical stimulation of the inferior centralis nucleus of the raphe in the cat. Pain 1: 139–145, 1975.
 647. Oliveras, J. L., A. Woda, G. Guilbaud, and J. M. Besson. Inhibition of the jaw opening reflex by electrical stimulation of the periaquaeductal gray matter in the awake, unrestrained cat. Brain Res. 72: 328–331, 1974.
 648. Orne, M. T. Hypnotic methods for managing pain. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 847–856.
 649. Otsuka, M., S. Konishi, M. Yanagisawa, A. Tsunoo, and H. Akagi. Role of substance P as a sensory transmitter in spinal cord and sympathetic ganglia. In: Substance P in the Nervous System, edited by R. Porter and M. O'Connor. London: Pitman, 1982, p. 13–34.
 650. Ottersen, O. P., and J. Storm‐Mathisen. Glutamate‐ and GABA‐containing neurons in the mouse and rat brain, as demonstrated with a new immunocytochemical technique. J. Comp. Neurol. 229: 374–392, 1984.
 651. Palmer, M. R., D. H. Morris, D. A. Taylor, J. M. Stewart, and B. J. Hoffer. Electrophysiological effects of enkephalin analogs in rat cortex. Life Sci. 23: 851–860, 1978.
 652. Pearson, J. A., D. E. Taylor, and D. M. Janzen. An inhibitory pathway from locus coeruleus to the spinal cord of the rat (Abstract). Proc. Can. Fed. Biol. Soc. 21: 55, 1978.
 653. Pedigo, N. W., and W. L. Dewey. Acetylcholine induced antinociception: comparisons to opiate analgesia. In: Advances in Behavioral Biology. Cholinergic Mechanisms, edited by G. Pepeu and H. Ladinsky. New York: Plenum, 1981, vol. 25, p. 795–807.
 654. Pepper, C. M., and G. Henderson. Opiates and opioid peptides hyperpolarize locus coeruleus neurons in vitro. Science 209: 394–396, 1980.
 655. Perl, E. R. Pain and nociception. In: Handbook of Physiology. The Nervous System. Sensory Processes, edited by I. Darian‐Smith. Bethesda, MD: Am. Physiol. Soc., 1983, vol. III, pt. 2, chapt. 20, p. 915–975.
 656. Perl, E. R. Characterization of nociceptors and their activation on neurons in the superficial dorsal horn: first step for the sensation of pain. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 23–51.
 657. Perl, E. R., and D. G. Whitlock. Somatic stimuli exciting spinothalamic projections to thalamic neurons in cat and monkey. Exp. Neurol. 3: 256–296, 1961.
 658. Pert, A. Psychopharmacology of analgesia and pain. In: Developments in Neurology. Pain, Discomfort and Humanitarian Care, edited by L. K. Y. Ng and J. J. Bonica. Amsterdam: Elsevier/North‐Holland, 1980, vol. 4, p. 138–190.
 659. Pert, A., R. Dionne, L. Ng, E. Bragin, T. W. Moody, and C. B. Pert. Alterations in rat central nervous system endorphins following transauricular electroacupuncture. Brain Res. 224: 83–93, 1981.
 660. Pert, A., T. W. Moody, C. B. Pert, L. A. Dewald, and J. Rivier. Bombesin receptor distribution in brain and effects on nociception and locomotor activity. Brain Res. 193: 209–220, 1980.
 661. Pert, A., and M. Walter. Comparison between naloxone reversal of morphine and electrical stimulation induced analgesia in the rat mesencephalon. Life Sci. 19: 1023–1032, 1976.
 662. Pertovaara, A., P. Kemppainen, G. Johansson, and S. L. Karonen. Dental analgesia produced by non‐painful, low‐frequency stimulation is not influenced or reversed by naloxone. Pain 13: 379–384, 1982.
 663. Peschanski, M., G. Guilbaud, and M. Gautron. Neuronal responses to cutaneous electrical and noxious mechanical stimuli in the nucleus reticularis thalami of the rat. Neurosci. Lett. 20: 165–170, 1980.
 664. Peschanski, M., G. Guilbaud, and M. Gautron. Posterior intralaminar region in rat: neuronal responses to noxious and non‐noxious cutaneous stimuli. Exp. Neurol. 72: 226–238, 1981.
 665. Peschanski, M., G. Guilbaud, M. Gautron, and J. M. Besson. Encoding of noxious heat messages in neurons of the ventrobasal thalamic complex of the rat. Brain Res. 197: 401–413, 1980.
 666. Petsche, U., E. Fleischer, F. Lembeck, and H. O. Handwerker. The effect of capsaicin applied to a peripheral nerve on impulse conduction in functionally identified afferent nerve fibers. Brain Res. 265: 223–240, 1983.
 667. Pickel, V. M., T. H. Joh, D. J. Reis, S. E. Leeman, and R. J. Miller. Electron microscopic localisation of substance P and enkephalin in axon terminals related to dendrites of catecholaminergic neurons. Brain Res. 160: 387–400, 1978.
 668. Pickel, V. M., D. J. Reis, and S. E. Leeman. Ultrastructural localization of substance P in neurons of rat spinal cord. Brain Res. 122: 534–540, 1977.
 669. Pierau, F. K., and P. Zimmermann. Action of a GABA‐derivative on postsynaptic potentials and membrane properties of cat's spinal motoneurones. Brain Res. 54: 376–380, 1973.
 670. Pierce, E. T., W. E. Foote, and J. A. Hobson. The efferent connection of the nucleus raphe dorsalis. Brain Res. 107: 137–144, 1976.
 671. Piercey, M. F., F. J. Einspahr, P. J. K. Dobry, L. A. Schroeder, and R. P. Hollister. Morphine does not antagonize the substance P mediated excitation of dorsal horn neurons. Brain Res. 186: 421–434, 1980.
 672. Piercey, M. F., and R. P. Hollister. Effects of intravenous baclofen on dorsal horn neurons of spinal cats. Eur. J. Pharmacol. 53: 379–385, 1979.
 673. Piercey, M. F., L. A. Schroeder, K. Folkers, J. L. Xu, and J. Hörig. Sensory and motor functions of spinal cord substance P. Science 214: 1361–1363, 1981.
 674. Poggio, G. F., and V. B. Mountcastle. A study of the functional contributions of the lemniscal and spinothalamic systems to somatic sensibility. Bull. Johns Hopkins Hosp. 106: 266–316, 1960.
 675. Poggio, G. F., and V. B. Mountcastle. The functional properties of ventrobasal thalamic neurons studied in unanesthetized monkeys. J. Neurophysiol. 26: 775–806, 1963.
 676. Pollin, B., and D. Albe‐Fessard. Organization of somatic thalamus in monkeys with and without section of dorsal spinal tracts. Brain Res. 173: 431–449, 1979.
 677. Pomeranz, B., R. Cheng, and P. Law. Acupuncture reduces electrophysiological and behavioural responses to noxious stimuli: pituitary is implicated. Exp. Neurol. 54: 172–178, 1977.
 678. Pomeranz, B., and D. Chiu. Naloxone blockade of acupuncture analgesia: endorphin implicated. Life Sci. 19: 1757–1762, 1976.
 679. Pomeranz, B., and N. Gurevich. Effects of enkephalin analogues and naloxone on cat spinal cord dorsal root potentials. Eur. J. Pharmacol. 60: 307–314, 1979.
 680. Pomeranz, B., and D. Paley. Electroacupuncture hypalgesia is mediated by afferent nerve impulses: an electrophysiological study in mice. Exp. Neurol. 66: 398–402, 1979.
 681. Pomeroy, S. L., and M. M. Behbehani. Physiologic evidence for a projection from periaquaeductal gray to nucleus raphe magnus in the rat. Brain Res. 176: 143–147, 1979.
 682. Price, D. D. Characteristics of second pain and flexion reflexes indicative of prolonged central summation. Exp. Neurol. 37: 371–387, 1972.
 683. Price, D. D. Roles of psychophysics, neuroscience, and experiential analysis in the study of pain. In: Advances in Pain Research and Therapy, Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 341–355.
 684. Price, D. D., and R. Dubner. Neurons that subserve the sensory discriminative aspect of pain. Pain 3: 307–388, 1977.
 685. Price, D. D., R. Dubner, R. Hayes, M. Ruda, and J. W. Hu. Trigeminothalamic and spinothalamic neurons that subserve sensory discrimination aspects of pain. In: Pain in the Trigeminal Region, edited by D. J. Anderson and B. Matthews. Amsterdam: Elsevier/North‐Holland, 1977, p. 225–232.
 686. Price, D. D., R. Dubner, and J. W. Hu. Trigeminothalamic neurons in nucleus caudalis responsive to tactile, thermal, and nociceptive stimulation of monkey's face. J. Neurophysiol. 39: 936–953, 1976.
 687. Price, D. D., H. Hayashi, R. Dubner, and M. A. Ruda. Functional relationships between neurons of marginal and substantia gelatinosa layers of primate dorsal horn. J. Neurophysiol. 42: 1590–1608, 1979.
 688. Price, D. D., R. L. Hayes, M. Ruda, and R. Dubner. Spatial and temporal transformations of input to spinothalamic tract neurons and their relation to somatic sensations. J. Neurophysiol. 41: 933–947, 1978.
 689. Price, D. D., J. W. Hu, R. Dubner, and R. Gracely. Peripheral suppression of first pain and central summation of second pain evoked by noxious heat pulses. Pain 3: 57–68, 1977.
 690. Price, D. D., and D. J. Mayer. Neurophysiological characterization of the anterolateral quadrant neurons subserving pain in M. mulatta. Pain 1: 59–72, 1975.
 691. Price, G. W., G. P. Wilkin, M. J. Turnbull, and N. G. Bowery. Are baclofen‐sensitive GABA‐B receptors present on primary afferent terminals of the spinal cord? Nature London 307: 71–73, 1984.
 692. Price, J., and A. W. Mudge. A subpopulation of rat dorsal root ganglion neurones is catecholaminergic. Nature London 301: 241–243, 1983.
 693. Prieto, G. J., J. T. Cannon, and J. C. Liebeskind. N. raphe magnus lesions disrupt stimulation‐produced analgesia from ventral but not dorsal midbrain areas in the rat. Brain Res. 261: 53–57, 1983.
 694. Procacci, P. History of pain concept. In: Pain and Society, edited by H. W. Kosterlitz and L. Y. Terenius. Weinheim, West Germany: Chemie, 1980, p. 3–12. (Dahlem Konferenzen.)
 695. Proudfit, H. K. Reversible inactivation of raphe magnus neurons: effects on nociceptive threshold and morphine‐induced analgesia. Brain Res. 201: 459–464, 1980.
 696. Proudfit, H. K., and E. G. Anderson. Influence of serotonin antagonists on bulbospinal systems. Brain Res. 61: 331–341, 1973.
 697. Proudfit, H. K., and E. G. Anderson. New long latency bulbospinal evoked potentials blocked by serotonin antagonists. Brain Res. 65: 542–546, 1974.
 698. Proudfit, H. K., and E. G. Anderson. Morphine analgesia: blockade by raphe magnus lesions. Brain Res. 98: 612–618, 1975.
 699. Proudfit, H. K., and D. L. Hammond. Alterations in nociceptive threshold and morphine‐induced analgesia produced by intrathecally administered amine antagonists. Brain Res. 218: 393–399, 1981.
 700. Proudfit, H. K., A. A. Larson, and E. G. Anderson. The role of GABA and serotonin in the mediation of raphe‐evoked spinal cord dorsal root potentials. Brain Res. 195: 149–165, 1980.
 701. Proudfit, H. K., and R. A. Levy. Delimitation of neuronal substrates necessary for the analgesic action of baclofen and morphine. Eur. J. Pharmacol. 47: 159–166, 1978.
 702. Puil, E. A. S‐glutamate: its interactions with spinal neurons. Brain Res. 228: 229–322, 1981.
 703. Ralston, H. J. III., Synaptic organization of spinothalamic tract projections to the thalamus, with special reference to pain. In: Advances in Pain Research and Therapy, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 183–195.
 704. Randic, M., and V. Miletic. Effect of substance P on cat dorsal horn neurons activated by noxious stimuli. Brain Res. 128: 164–169, 1977.
 705. Randic, M., and V. Miletic. Depressant actions of methionine‐enkephalin and somatostatin in cat dorsal horn neurones activated by noxious stimuli. Brain Res. 152: 196–202, 1978.
 706. Randic, M., and H. H. Yu. Effects of 5‐hydroxytryptamine and bradykinin in cat dorsal horn neurones activated by noxious stimuli. Brain Res. 111: 197–203, 1976.
 707. Reddy, S. V. R., J. L. Maderdrut, and T. L. Yaksh. Spinal cord pharmacology of adrenergic agonist‐mediated antinociception. J. Pharmacol. Exp. Ther. 213: 525–533, 1980.
 708. Reddy, S. V. R., and T. L. Yaksh. Spinal noradrenergic terminal system mediates antinociception. Brain Res. 189: 391–401, 1980.
 709. Reichlin, S. Somatostatin. In: Brain Peptides, edited by D. T. Krieger, M. J. Brownstein, and J. B. Martin. New York: Wiley, 1983, p. 711–752.
 710. Renaud, L. P., J. B. Martin, and P. Brazeau. Depressant action of TRH, LHRH and somatostatin on activity of central neurones. Nature London 255: 233–235, 1975.
 711. Rexed, B. The cytoarchitectonic organization of the spinal cord in the cat. J. Comp. Neurol. 96: 415–496, 1952.
 712. Rexed, B. A cytoarchitectonic atlas of the spinal cord in the cat. J. Comp. Neurol. 100: 297–380, 1954.
 713. Reynolds, D. V. Surgery in the rat during electrical analgesia induced by focal brain stimulation. Science 164: 444–445, 1969.
 714. Reynolds, D. V., and A. I. Sjöberg. Neuroelectric Research. Springfield, IL: Thomas, 1971.
 715. Rhodes, D. L., and J. C. Liebeskind. Analgesia from rostral brain stem stimulation in the rat. Brain Res. 143: 521–532, 1978.
 716. Ribeiro‐Da‐Silva, A., and A. Coimbra. Neuronal uptake of [3H]GABA and [3H]glycine in laminae I‐III (substantia gelatinosa Rolandi) of the rat spinal cord. An autoradiographic study. Brain Res. 188: 449–464, 1980.
 717. Richardson, D. E., and H. Akil. Pain reduction by electrical brain stimulation in man. Pt. 1. Acute administration in periaqueductal and periventricular sites. J. Neurosurg. 47: 178–183, 1977.
 718. Richardson, D. E., and H. Akil. Pain reduction by electrical brain stimulation in man. Pt. 2. Chronic self‐administration in the periventricular gray matter. J. Neurosurg. 47: 184–194, 1977.
 719. Rivot, J. P., A. Chaouch, and J. M. Besson. The influence of naloxone on the C‐fiber response of dorsal horn neurons and their inhibitory control by raphe magnus stimulation. Brain Res. 176: 355–364, 1979.
 720. Rivot, J. P., C. Y. Chiang, and J. M. Besson. Increase of serotonin metabolism within the dorsal horn of the spinal cord during nucleus raphe magnus stimulation, as revealed by in vivo electrochemical detection. Brain Res. 238: 117–126, 1982.
 721. Roberts, L. A., C. Bayer, and B. R. Komisaruk. Strychnine antagonizes vaginal stimulation‐produced analgesia at the spinal cord. Life Sci. 36: 2017–2023, 1985.
 722. Robinson, C. J., and H. Burton. Somatic submodality distribution within the second somatosensory (SII), 7b, retroinsular, postauditory, and granular insular cortical areas of the M. fascicularis. J. Comp. Neurol. 192: 93–108, 1980.
 723. Rodriguez, R. E., T. E. Salt, P. M. B. Cahusac, and R. G. Hill. The behavioural effects of intrathecally administered (D‐Pro2,D‐Trp7,9)‐substance P, an analogue with presumed antagonist actions, in the rat. Neuropharmacology 22: 173–176, 1983.
 724. Roques, B. P., M. C. Fournie‐Zaluski, E. Soroca, J. M. Lecomte, B. Malfroy, C. Llorens, and J.‐C. Schwartz. The enkephalinase inhibitor thiorphan shows antinociceptive activity in mice. Nature London 288: 286–288, 1980.
 725. Rosell, S., L. Olgart, B. Gazelius, P. Panopoulos, K. Folkers, and J. Hörig. Inhibition of antidromic and substance P‐induced vasodilation by a substance P antagonist. Acta Physiol. Scand. 111: 381–382, 1981.
 726. Ross, C. A., D. M. Armstrong, D. A. Ruggiero, V. M. Pickel, T. H. Joh, and D. J. Reis. Adrenaline neurons in the rostral ventrolateral medulla innervate thoracic spinal cord: a combined immunocytochemical and retrograde transport demonstration. Neurosci. Lett. 25: 257–262, 1981.
 727. Rossier, J. Opioid peptides have found their roots. Nature London 298: 221–222, 1982.
 728. Rossier, J., E. Battenberg, Q. Pittman, A. Bayon, L. Koda, R. Miller, R. Guillemin, and F. E. Bloom. Hypothalamic enkephalin neurones may regulate the neurohypophysis. Nature London 277: 653–655, 1979.
 729. Rossier, J., E. D. French, C. Rivier, N. Ling, R. Guillemin, and F. E. Bloom. Foot‐shock induced stress increases beta‐endorphin levels in rat blood but not brain. Nature London 270: 618–620, 1977.
 730. Ruch, T. C. Pathophysiology of pain. In: Physiology and Biophysics (20th ed.), edited by T. C. Ruch and H. D. Patton. Philadelphia, PA: Saunders, 1979, vol. 1, p. 313–316.
 731. Ruda, M. A. Opiates and pain pathways: demonstration of enkephalin synapses and dorsal horn projection neurons. Science 215: 1523–1525, 1982.
 732. Ruda, M. A., J. Coffield, G. J. Bennett, and R. Dubner. Role of serotonin (5‐HT) and enkephalin (ENK) in trigeminal and spinal pain pathways. J. Dent. Res. 62: 691, 1983.
 733. Ruda, M. A., J. Coffield, and R. Dubner. Demonstration of postsynaptic opioid modulation of thalamic projection neurons by the combined techniques of retrograde horseradish peroxidase and enkephalin immunocytochemistry. J. Neurosci. 4: 2117–2132, 1984.
 734. Ruda, M. A., and S. Gobel. Ultrastructural characterization of axonal endings in the substantia gelatinosa which take up (3H)serotonin. Brain Res. 184: 57–83, 1980.
 735. Rustioni, A., N. L. Hayes, and S. O'Neil. Dorsal column nuclei and ascending spinal afferents in macaques. Brain 102: 95–125, 1979.
 736. Sachs, C., and G. Jonsson. Mechanisms of action of 6‐hydroxydopamine. Biochem. Pharmacol. 24: 1–8, 1975.
 737. Sagen, J., and H. K. Proudfit. Hypoalgesia induced by blockage of noradrenergic projections to the raphe magnus: reversal by blockade of noradrenergic projections to the spinal cord. Brain Res. 223: 391–396, 1981.
 738. Salar, G., I. Job, S. Mingrino, A. Bosio, and M. Trabucchi. Effect of transcutaneous electrotherapy on CSF beta‐endorphin content in patients without pain problems. Pain 10: 169–172, 1981.
 739. Salt, T. E., and R. G. Hill. Vasoactive intestinal polypeptide (VIP) applied to microiontophoresis excites single neurones in the trigeminal nucleus caudalis of the rat. Neuropeptides 1: 403–408, 1981.
 740. Salt, T. E., and R. G. Hill. The effects of C‐terminal fragments of cholecystokinin on the firing of single neurones in the caudal trigeminal nucleus of the rat. Neuropeptides 2: 301–306, 1982.
 741. Salt, T. E., and R. G. Hill. Pharmacological differentiation between responses of rat medullary dorsal horn neurones to noxious mechanical and noxious thermal cutaneous stimuli. Brain Res. 263: 167–171, 1983.
 742. Samanin, R., and S. Bernasconi. Effects of intraventricularly injected 6‐OH dopamine or midbrain raphe lesion on morphine analgesia in rats. Psychopharmacologia 25: 175–182, 1972.
 743. Samanin, R., W. Gumulka, and L. Valzelli. Reduced effect of morphine in midbrain raphe lesioned rats. Eur. J. Pharmacol. 10: 339–343, 1970.
 744. Samanin, R., and L. Valzelli. Increase of morphine‐induced analgesia by stimulation of the nucleus raphe dorsalis. Eur. J. Pharmacol. 16: 298–302, 1971.
 745. Sandberg, D. E., and M. Segal. Pharmacological analysis of analgesia and self‐stimulation elicited by electrical stimulation of catecholamine nuclei in the rat brain. Brain Res. 152: 529–542, 1978.
 746. Sandkühler, J., and G. F. Gebhart. Relative contribution of the nucleus raphe magnus and adjacent medullary reticular formation to the inhibition by stimulation in the periaqueductal gray of a spinal nociceptive reflex in the pentobarbital‐anaesthetized rat. Brain Res. 305: 77–87, 1984.
 747. Sano, K. Surgery of the hypothalamus—in commemoration of Otfrid Foerster. In: Recent Progress in Neurological Surgery, edited by K. Sano, S. Ishii, and D. Le Vay. New York: Elsevier, 1974, p. 210–218.
 748. Sasa, M., K. Hunekiyo, Y. Osumi, and S. Takoari. Attenuation of morphine analgesia in rats with lesions of the locus coeruleus and dorsal raphe nucleus. Eur. J. Pharmacol. 42: 53–62, 1977.
 749. Sasa, M., S. Igarashi, and S. Takaori. Influence of the locus coeruleus on interneurons in the spinal trigeminal nucleus. Brain Res. 125: 369–375, 1977.
 750. Sastry, B. R. Morphine and met‐enkephalin effects on sural A delta afferent terminal excitability. Eur. J. Pharmacol. 50: 269–273, 1978.
 751. Sastry, B. R. Presynaptic effects of morphine and methionine enkephalin in feline spinal cord. Neuropharmacology 18: 367–375, 1979.
 752. Sastry, B. R. Substance P effects on spinal nociceptive neurons. Life Sci. 24: 2169–2178, 1979.
 753. Satoh, M., A. Akaike, T. Nakazawa, and H. Takagi. Evidence for the involvement of separate mechanisms in the production of analgesia by electrical stimulation of the nucleus paragigantocellularis and nucleus raphe magnus in the rat. Brain Res. 194: 525–529, 1980.
 754. Satoh, M., A. Akaike, and H. Takagi. Excitation by morphine and enkephalin of single neurons of nucleus reticularis paragigantocellularis in the rat: a probable mechanism of analgesic action of opioids. Brain Res. 169: 406–410, 1979.
 755. Satoh, M., S. I. Kawajiri, Y. Ukai, and M. Yamamoto. Selective and nonselective inhibition by enkephalins and noradrenaline of nociceptive responses of lamina V type neurons in the spinal dorsal horn of rabbit. Brain Res. 177: 384–387, 1979.
 756. Satoh, M., N. Nakamura, and H. Takagi. Effect of morphine on bradykinin‐induced unitary discharges in the spinal cord of the rabbit. Eur. J. Pharmacol. 16: 245–247, 1971.
 757. Satoh, M., R. Oku, and A. Akaike. Analgesia produced by microinjection of L‐glutamate into the rostral ventromedial bulbar nuclei of the rat and its inhibition by intrathecal alpha‐adrenergic blocking agents. Brain Res. 261: 361–364, 1983.
 758. Satoh, M., and H. Takagi. Enhancement by morphine of the central descending inhibitory influence on spinal sensory transmission. Eur. J. Pharmacol. 14: 60–65, 1971.
 759. Satoh, M., W. Zieglgänsberger, and A. Herz. Actions of opiates upon single unit activity in the cortex of naive and tolerant rats. Brain Res. 115: 99–110, 1976.
 760. Schaible, H.‐G., and R. F. Schmidt. Activation of groups III and IV sensory units in medial articular nerve by local mechanical stimulation of knee joint. J. Neurophysiol. 49: 35–44, 1983.
 761. Schaible, H.‐G., and R. F. Schmidt. Responses of fine medial articular nerve afferents to passive movements of knee joint. J. Neurophysiol. 49: 1118–1126, 1983.
 762. Schmidt, R. F. Presynaptic inhibition in the vertebrate central nervous system. Ergeb. Physiol. Biol. Chem. Exp. Pharmakol. 63: 20–101, 1971.
 763. Schultzberg, M., T. Hökfelt, and J. Lundberg. Coexistence of classical transmitters and peptides in the central and peripheral nervous system. Br. Med. Bull. 38: 309–313, 1982.
 764. Schultzberg, M., T. Hökfelt, J. Lundberg, L. Terenius, L. G. Elfirm, and R. Elde. Enkephalin‐like immunoreactivity in nerve terminals in sympathetic ganglia and adrenal medulla and in adrenal medullary gland cells. Acta Physiol. Scand. 103: 475–477, 1978.
 765. Scott‐Young, W., S. J. Bird, and M. J. Kuhar. Iontophoresis of methionine‐enkephalin in the locus coeruleus area. Brain Res. 129: 366–370, 1977.
 766. Segal, M., and D. Sandberg. Analgesia produced by electrical stimulation of catecholamine nuclei in the rat brain. Brain Res. 123: 369–372, 1977.
 767. Senba, E., S. Shiosaka, Y. Hara, S. Inagaki, M. Sakanaka, K. Takatsuki, Y. Kawai, and M. Tohyama. Ontogeny of the peptidergic system in the rat spinal cord: immunohistochemical analysis. J. Comp. Neurol. 208: 54–66, 1982.
 768. Sessle, B. J., R. Dubner, L. F. Greenwood, and G. E. Lucier. Descending influences of periaqueductal gray matter and somatosensory cerebral cortex on neurons in trigeminal brain stem nucleus. Can. J. Physiol. Pharmacol. 54: 66–69, 1975.
 769. Sessle, B. J., and J. W. Hu. Raphe‐induced suppression of the jaw‐opening reflex and single neurons in trigeminal subnucleus oralis, and influence of naloxone and subnucleus caudalis. Pain 10: 19–36, 1981.
 770. Seybold, V., and R. P. Elde. Neurotensin immunoreactivity in the superficial laminae of the dorsal horn of the rat. I. Light microscopic studies of cell bodies and proximal dendrites. J. Comp. Neurol. 205: 89–100, 1982.
 771. Seybold, V., and B. Maley. Ultrastructural study of Neurotensin immunoreactivity in the superficial laminae of the dorsal horn of the rat. Peptides 5: 1179–1189, 1984.
 772. Shah, Y., and J. O. Dostrovsky. Electrophysiological evidence for a projection of the periaqueductal gray matter to nucleus raphe magnus in cat and rat. Brain Res. 193: 534–538, 1980.
 773. Shealy, C. N., J. T. Mortimer, and J. B. Reswick. Electrical inhibition of pain by stimulation on the dorsal column: preliminary clinical reports. Anesth. Analg. 46: 489–491, 1967.
 774. Sherrington, C. S. The Integrative Action of the Nervous System. New Haven, CT: Yale Univ. Press, 1906. (Yale paperbound, 1981.)
 775. Shigenaga, Y., and R. Inoki. Effect of morphine on single unit responses in ventrobasal complex (VB) and posterior nuclear group (PO) following tooth pulp stimulation. Brain Res. 103: 152–156, 1976.
 776. Shiomi, H., H. Murakami, and H. Takagi. Morphine analgesia and the bulbospinal serotonergic system: increase in concentration of 5‐hydroxy‐indolacetic acid in the rat spinal cord with analgesics. Eur. J. Pharmacol. 52: 335–344, 1978.
 777. Shiomi, H., and H. Takagi. Morphine analgesia and bulbospinal noradrenergic system: increase in the concentration of normetanephrine in the spinal cord of the rat caused by analgesia. Br. J. Pharmacol. 52: 519–526, 1974.
 778. Shults, C. W., R. Quirion, B. Chronwall, T. N. Chase, and T. L. O'Donohue. A comparison of the anatomical distribution of substance P and substance P receptors in the rat central nervous system. Peptides 5: 1097–1128, 1984.
 779. Siggins, G. R., J. F. McGinty, J. H. Morrison, Q. J. Pittman, W. Zieglgänsberger, P. J. Magistretti, and D. L. Gruol. The role of neuropeptides in the hippocampal formation. In: Advances in Biochemical Psychopharmacology. Regulatory Peptides: From Molecular Biology to Function, edited by E. Costa and M. Trabucchi. New York: Raven, 1982, vol. 33, p. 419–422.
 780. Siggins, G. R., and W. Zieglgänsberger. Morphine and opioid peptides reduce inhibitory synaptic potentials in hippocampal pyramidal cells in vitro without alteration of membrane potential. Proc. Natl. Acad. Sci. USA 78: 5235–5239, 1981.
 781. Sinclair, J. G., R. E. Fox, S. S. Mokha, and A. Iggo. The effect of naloxone on the inhibition of nociceptor driven neurones in the cat spinal cord. Q. J. Exp. Physiol. 65: 181–188, 1980.
 782. Sjölund, B., and M. Eriksson. Electro‐acupuncture and endogenous morphines. Lancet 2: 1085, 1976.
 783. Sjölund, B., and M. Eriksson. The influence of naloxone on analgesia produced by peripheral conditioning stimulation. Brain Res. 173: 295–301, 1979.
 784. Sjölund, B., L. Terenius, and M. Eriksson. Increased cerebrospinal fluid levels of endorphins after electro‐acupuncture. Acta Physiol. Scand. 100: 382–384, 1977.
 785. Skagerberg, G., A. Björklund, L. O. Lindvall, and R. H. Schmidt. Origin and termination of the diencephalo‐spinal dopamine system in the rat. Brain Res. Bull. 9: 237–244, 1982.
 786. Skrabanek, P., and D. Powell. Substance P. Edinburgh: Churchill Livingstone, 1982.
 787. Soja, P. J., and J. G. Sinclair. Spinal vs supraspinal actions of morphine on cat spinal cord multireceptive neurons. Brain Res. 273: 1–7, 1983.
 788. Spiaggia, A., R. J. Bodnar, D. D. Kelly, and M. Glusman. Opiate and non‐opiate mechanisms of stress‐induced analgesia: cross tolerance between stressors. Pharmacol. Biochem. Behav. 10: 761–765, 1979.
 789. Spiler, I. J., and M. E. Molitch. Lack of modulation of pituitary hormone stress response by neural pathways involving opiate receptors. J. Clin. Endocrinol. Metab. 50: 516–520, 1980.
 790. Stanzione, P., and W. Zieglgänsberger. Action of neurotensin on spinal cord neurons in the rat. Brain Res. 268: 111–118, 1983.
 791. Steinman, J. L., B. R. Komisaruk, T. L. Yaksh, and G. M. Tyce. Vaginal stimulation‐produced analgesia is mediated by spinal norepinephrine and serotonin in rats. Soc. Neurosci. Abstr. 6: 454, 1980.
 792. Stewart, D., J. Thomson, and I. Oswald. Acupuncture analgesia: an experimental investigation. Br. Med. J. 1: 67–70, 1977.
 793. Stewart, J. M., C. J. Getto, K. Neldner, E. B. Reeve, W. A. Krivoy, and E. Zimmermann. Substance P and analgesia. Nature London 262: 784–785, 1976.
 794. Stone, T. W. Physiological roles for adenosine and ATP in the nervous system. Neuroscience 6: 523–555, 1981.
 795. Strahlendorf, H. K., J. C. Strahlendorf, and C. D. Barnes. Endorphin‐mediated inhibition of locus coeruleus neurons. Brain Res. 191: 284–288, 1980.
 796. Strahlendorf, J. C., H. K. Strahlendorf, R. E. Kingsley, J. Gintantas, and C. D. Barnes. Facilitation of lumbar monosynaptic reflexes by locus coeruleus stimulation. Neuropharmacology 19: 225–230, 1980.
 797. Sullivan, T. L., and A. Pert. Analgesic activity of non opiate neuropeptides following injections into the rat periaqueductal gray matter. Soc. Neurosci. Abstr. 7: 504, 1981.
 798. Sumal, K. K., V. M. Pickel, R. J. Miller, and D. J. Reis. Enkephalin‐containing neurons in substantia gelatinosa of spinal trigeminal complex: ultrastructure and synaptic interaction with primary sensory afferents. Brain Res. 248: 223–236, 1982.
 799. Sun, C. L., and C. B. Gatipon. Effects of morphine sulphate on medial bulboreticular response to peripherally applied noxious stimuli. Exp. Neurol. 52: 1–12, 1976.
 800. Sutor, B., and W. Zieglgänsberger. Actions of D‐ala2‐D‐leu5‐enkephalin and dynorphin A (1‐17) on neocortical neurons in vitro. Neuropeptides 5: 241–244, 1984.
 801. Suzue, T., and T. Jessell. Opiate analgesics and endorphins inhibit rat dorsal root potential in vitro. Neurosci. Lett. 16: 161–166, 1980.
 802. Swanson, L. W. Immunohistochemical evidence for a neurophysin‐containing autonomic pathway arising in the paraventricular nucleus of the hypothalamus. Brain Res. 128: 346–353, 1977.
 803. Swaynok, J., C. Pinsky, and F. S. La Bella. Minireview on the specificity of naloxone as an opiate antagonist. Life Sci. 25: 1621–1632, 1979.
 804. Sweet, W. H. Intracranial electrical stimulation for relief of chronic intractable pain. Prog. Neurol. Surg. 8: 258–269, 1977.
 805. Sweet, W. H. Animal models of chronic pain: their possible validation from human experience with posterior rhizotomy and congenital analgesia. (Part I of the second John J. Bonica Lecture). Pain 10: 275–295, 1981.
 806. Sweet, W. H. Cerebral localization of pain. In: New Perspectives in Cerebral Location, edited by R. A. Thompson and J. P. Green. New York: Raven, 1982, p. 205–240.
 807. Sweetnam, P. M., J. H. Neale, J. L. Barker, and A. Goldstein. Localization of immunoreactive dynorphin in neurons cultured from spinal cord and dorsal root ganglia. Proc. Natl. Acad. Sci. USA 79: 6742–6746, 1982.
 808. Szentagothai, J. Neuronal and synaptic arrangement in the substantia gelatinosa Rolandi. J. Comp. Neurol. 122: 219–239, 1964.
 809. Szolcsanyi, J., A. Jancso‐Gabor, and F. Joo. Functional and fine structural characteristics of the sensory neurone blocking effect of capsaicin. Naunyn‐Schmiedebergs Arch. Exp. Pathol. Pharmakol. 287: 157–169, 1975.
 810. Takagi, H., T. Doi, and A. Akaike. Microinjection of morphine into the medial parts of the bulbar reticular formation in rabbit and rat: inhibitory effects on lamina V cells of spinal dorsal horn and behavioural analgesia. In: Opiates and Endogenous Opioid Peptides, edited by H. W. Kosterlitz. Amsterdam: Elsevier/North‐Holland, 1976, p. 191–198.
 811. Takagi, H., M. Matsamura, A. Yanai, and K. Ogiu. The effect of analgesics on the spinal reflex activity of the cat. Jpn. J. Pharmacol. 4: 76–187, 1955.
 812. Takagi, H., M. Satoh, A. Akaike, T. Shibata, and Y. Kuraishi. The nucleus reticularis gigantocellularis of the medulla oblongata is a highly sensitive site in the production of morphine analgesia in the rat. Eur. J. Pharmacol. 45: 91–92, 1977.
 813. Takahashi, M., and T. Yokota. Convergence of cardiac and cutaneous afferents onto neurons in the dorsal horn of the spinal cord in the cat. Neurosci. Lett. 38: 251–256, 1983.
 814. Takahashi, T., and M. Otsuka. Regional distribution of substance P in the spinal cord and nerve roots of the cat and the effect of dorsal root section. Brain Res. 87: 1–11, 1975.
 815. Tan, S. Y. Cognitive and cognitive‐behavioural methods for pain control: a selective review. Pain 12: 201–228, 1982.
 816. Tang, A. H., and M. J. Schoenfeld. Comparison of subcutaneous spinal subarachnoid injections of morphine and naloxone on analgesic tests in the rat. Eur. J. Pharmacol. 52: 215–223, 1978.
 817. Tasker, R. R., T. Tsuda, and P. Hawrylyshyn. Clinical neurophysiological investigation of deafferentiation pain. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. C. Benedetti. New York: Raven, 1983, vol. 5, p. 713–738.
 818. Taub, A. Acupuncture “anesthesia”: a critical review. In: Advances in Pain Research and Therapy. Proceedings of the First World Congress on Pain, edited by J. J. Bonica and D. Albe‐Fessard. New York: Raven, 1976, vol. 1, p. 743–748.
 819. Terenius, L. Neuropeptides in human cerebrospinal fluid. Relations to pain. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 509–517.
 820. Teschemacher, H., P. Schubert, and A. Herz. Studies concerning the supraspinal site of action of morphine when inhibiting the hindleg flexion reflex. Neuropharmacology 12: 123–131, 1973.
 821. Toda, K., and M. Ichioka. Electroacupuncture: relations between forelimb afferent impulses and suppression of jaw‐opening reflex in the rat. Exp. Neurol. 61: 465–470, 1978.
 822. Toda, K., H. Suda, M. Ichioka, and A. Iriki. Local electrical stimulation: effective needling points for suppressing jaw opening reflex in rat. Pain 9: 199–207, 1980.
 823. Todd, A. J., and J. Millar. Receptive fields and responses to iontophoretically applied noradrenaline and 5‐hydroxytryptamine of units recorded in laminae I‐III of cat dorsal horn. Brain Res. 288: 159–167, 1983.
 824. Torebjörk, H. E., and R. G. Hallin. Perceptual changes accompanying controlled preferential blocking of A and C fiber responses in intact human skin nerves. Exp. Brain Res. 16: 321–332, 1973.
 825. Torebjörk, H. E., and J. L. Ochoa. Specific sensations evoked by activity in single identified sensory units in man. Acta Physiol. Scand. 110: 445–447, 1980.
 826. Torvik, A., and A. Brodal. The origin of reticulospinal fibers in the cat. An experimental study. Anat. Rec. 128: 113–138, 1957.
 827. Trevino, D. L., J. D. Coulter, and W. D. Willis. Location of cells of origin of spinothalamic tract in lumbar enlargement of the monkey. J. Neurophysiol. 36: 750–761, 1973.
 828. Tsou, K., and C. S. Jang. Studies on the site of analgesic action of morphine by intracerebral micro‐injection. Sci. Sin. 13: 1099–1109, 1964.
 829. Turner, J. A., and C. R. Chapman. Psychological interventions for chronic pain: a critical review. I. Relaxation, training, and biofeedback. Pain 12: 1–21, 1982.
 830. Turner, J. A., and C. R. Chapman. Psychological interventions for chronic pain: a critical review. II. Operant conditioning, hypnosis, and cognitive‐behavioural therapy. Pain 12: 23–46, 1982.
 831. Tyce, G. M., and T. L. Yaksh. Monoamine release from cat spinal cord by somatic stimuli: an intrinsic modulatory system. J. Physiol. London 314: 513–529, 1981.
 832. Uddenberg, N. Functional organization of long, second‐order afferents in the dorsal funiculus. Exp. Brain Res. 4: 377–382, 1968.
 833. Uhl, G. R., and S. H. Snyder. Neurotensin. In: Advances in Biochemical Psychopharmacology. Neurosecretion and Brain Peptides: Implications for Brain Function and Neurological Disease, edited by J. B. Martin, S. Reichlin, and K. L. Bick. New York: Raven, 1981, vol. 28, p. 87–106.
 834. Vane, J. R. Pain of inflammation: an introduction. In: Advances in Pain Research and Therapy. Proceedings of the Third World Congress on Pain, edited by J. J. Bonica, U. Lindblom, A. Iggo, L. E. Jones, and C. Benedetti. New York: Raven, 1983, vol. 5, p. 597–603.
 835. Van Hees, J., and J. M. Gybels. Pain related to single afferent C fibers from human skin. Brain Res. 48: 397–400, 1972.
 836. Vigouret, J., H. Teschemacher, and A. Herz. Differentiation between spinal and supraspinal sites of action of morphine when inhibiting the hindleg flexor reflex in rabbits. Neuropharmacology 12: 111–121, 1973.
 837. Villanueva, L., S. W. Cadden, and D. Le Bars. Evidence that diffuse noxious inhibitory control (DNIC) is mediated by a final post‐synaptic inhibitory mechanism. Brain Res. 298: 67–74, 1984.
 838. Viveros, O. H., E. J. Diliberto, Jr., E. Hazum, and K. J. Chang. Opiate‐like materials in the adrenal medulla: evidence for storage and secretion with catecholamines. Mol. Pharmacol. 16: 1101–1108, 1979.
 839. Walberg, F. Paths descending from the brain stem—an overview. In: Brain Stem Control of Spinal Mechanisms, edited by B. H. Sjölund and A. Björklund. Amsterdam: Elsevier, 1982, p. 1–28.
 840. Wall, P. D. The laminar organisation of dorsal horn and effects of descending impulses. J. Physiol. London 188: 403–423, 1967.
 841. Wall, P. D. The role of substantia gelatinosa as a gate control. In: Pain, edited by J. J. Bonica. New York: Raven, 1980, p. 208–231.
 842. Wall, P. D. Mechanisms of acute and chronic pain. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 95–104.
 843. Wall, P. D., and M. Fitzgerald. Effects of capsaicin applied locally to adult peripheral nerve. I. Physiology of peripheral nerve and spinal cord. Pain 11: 363–377, 1981.
 844. Wall, P. D., and M. Gutnick. Ongoing activity in peripheral nerves: the physiology and pharmacology of impulses originating from a neuroma. Exp. Neurol. 43: 580–593, 1974.
 845. Wall, P. D., and M. Gutnick. Properties of afferent nerve impulses originating from a neuroma. Nature London 248: 740–743, 1974.
 846. Wall, P. D., and S. B. McMahon. Microneuronography and its relation to perceived sensation. Pain 21: 209–229, 1985.
 847. Wall, P. D., E. G. Merrill, and T. L. Yaksh. Responses of single units in laminae 2 and 3 of cat spinal cord. Brain Res. 160: 245–260, 1979.
 848. Wall, P. D., and T. L. Yaksh. The effect of Lissauer tract stimulation on activity in dorsal and ventral roots. Exp. Neurol. 60: 570–583, 1978.
 849. Wang, J. K. Actinociceptive effect of intrathecally administered serotonin. Anesthesiology 47: 269–271, 1977.
 850. Wang, J. K., L. A. Nauss, and J. E. Thomas. Pain relief by intrathecally applied morphine in man. Anesthesiology 50: 149–151, 1979.
 851. Wang, R. Y., and G. K. Aghajanian. Antidromically identified serotonergic neurons in the rat midbrain raphe: evidence for collateral inhibition. Brain Res. 132: 147–151, 1977.
 852. Watkins, L. R., D. A. Cobelli, P. Faris, M. D. Aceto, and D. J. Mayer. Opiate vs non‐opiate footshock‐induced analgesia (FSIA): the body region shocked is a critical factor. Brain Res. 242: 299–308, 1982.
 853. Watkins, L. R., D. A. Cobelli, and D. J. Mayer. Classical conditioning of front paw and hind paw footshock‐induced analgesia (FSIA): naloxone reversibility and descending pathways. Brain Res. 243: 119–132, 1982.
 854. Watkins, L. R., D. A. Cobelli, and D. J. Mayer. Opiate vs non‐opiate footshock‐induced analgesia (FSIA): descending and intraspinal components. Brain Res. 245: 97–106, 1982.
 855. Watkins, L. R., D. A. Cobelli, H. H. Newsome, and D. J. Mayer. Footshock‐induced analgesia is dependent neither on pituitary nor sympathetic activity. Brain Res. 245: 81–96, 1982.
 856. Watkins, L. R., and D. J. Mayer. Organization of endogenous opiate and non‐opiate pain control systems. Science 216: 1185–1192, 1982.
 857. Watkins, L. R., E. G. Young, I. B. Kinscheck, and D. J. Mayer. The neuronal basis of footshock analgesia: the role of specific ventral medullary nuclei. Brain Res. 276: 305–315, 1983.
 858. Watson, S. J., H. Akil, V. E. Ghazarossian, and A. Goldstein. Dynorphin immunocytochemical localization in brain and peripheral nervous system: preliminary studies. Proc. Natl. Acad. Sci. USA 78: 1260–1263, 1981.
 859. Watson, S. J., H. Akil, C. W. Richard, and J. D. Barchas. Evidence for two separate opiate peptide neuronal systems and the coexistence of beta‐LPH, beta‐endorphin and ACTH immunoreactivities in the same hypothalamic neurones. Nature London 275: 226–228, 1978.
 860. Watson, S. J., H. Akil, S. Sullivan, and J. D. Barchas. Immunocytochemical localization of methionine enkephalin: preliminary observations. Life Sci. 21: 733–738, 1977.
 861. Watson, S. J., H. Khachaturian, and H. Akil. Comparison of the distribution of dynorphin systems and enkephalin systems in brain. Science 218: 1134–1136, 1982.
 862. Watson, S. J., H. Khachaturian, L. Taylor, W. Fischli, A. Goldstein, and H. Akil. Pro‐dynorphin peptides are found in the same neurons throughout rat brain: immunocytochemical study. Proc. Natl. Acad. Sci. USA 80: 891–894, 1983.
 863. Weber, E., K. A. Roth, C. J. Evans, J. K. Chang, and J. D. Barchas. Immunohistochemical localization of dynorphin (1–8) in hypothalamic magnocellular neurons: evidence for absence of proenkephalin. Life Sci. 31: 1761–1764, 1982.
 864. Weil‐Fugazza, J., F. Godefroy, and J. M. Besson. Changes in brain and spinal tryptophan and 5‐hydroxyindoleacetic acid levels following acute morphine administration in normal and arthritic rats. Brain Res. 175: 291–301, 1979.
 865. Welk, E., U. Petsche, E. Fleischer, and H. O. Handwerker. Altered excitability of afferent C‐fibers of the rat distal to a nerve site exposed to capsaicin. Neurosci. Lett. 38: 245–250, 1983.
 866. Werz, M. A., and R. L. Macdonald. Heterogenous sensitivity of cultured dorsal root ganglion neurones to opioid peptides selective for mu and delta opiate receptors. Nature London 299: 730–733, 1982.
 867. Werz, M. A., and R. L. Macdonald. Opioid peptides decrease calcium‐dependent action potential duration of mouse dorsal root ganglion neurons in cell culture. Brain Res. 239: 315–321, 1982.
 868. Wessendorf, M. W., H. K. Proudfit, and E. G. Anderson. The identification of serotonergic neurons in the nucleus raphe magnus by conduction velocity. Brain Res. 214: 168–173, 1981.
 869. West, D. C., and J. H. Wolstencroft. Location and conduction velocity of raphe spinal neurones in nucleus raphe magnus and raphe pallidus in the cat. Neurosci. Lett. 5: 147–151, 1977.
 870. Westlund, K. N., R. M. Bowker, M. G. Ziegler, and J. D. Coulter. Noradrenergic projections to the spinal cord of the rat. Brain Res. 263: 15–31, 1983.
 871. Westlund, K. N., R. M. Bowker, M. G. Ziegler, and J. D. Coulter. Origin and terminations of descending noradrenergic projections to the spinal cord of monkey. Brain Res. 292: 1–16, 1984.
 872. Westlund, K. N., and J. D. Coulter. Descending projections of the locus coeruleus and subcoeruleus/medial parabrachial nuclei in the monkey: axonal transport studies and dopamine‐hydroxylase immunocytochemistry. Brain Res. Rev. 2: 235–264, 1980.
 873. Wiklund, L., L. Leger, and M. Persson. Monoamine cell distribution in the cat brain stem. A fluorescence histochemical study with quantification of indolaminergic and locus coeruleus cell groups. J. Comp. Neurol. 203: 613–648, 1982.
 874. Willcockson, W. S., J. M. Chung, Y. Hori, K. H. Lee, and W. D. Willis. Effects of iontophoretically released amino acids and amines on primate spinothalamic tract cells. J. Neurosci. 4: 732–740, 1984.
 875. Willcockson, W. S., J. M. Chung, Y. Hori, K. H. Lee, and W. D. Willis. Effects of iontophoretically released peptides on primate spinothalamic tract cells. J. Neurosci. 4: 741–750, 1984.
 876. Willer, J. C., and B. Bussel. Evidence for a direct spinal mechanism in morphine‐induced inhibition of nociceptive reflexes in humans. Brain Res. 187: 212–215, 1980.
 877. Willer, J. C., H. Dehan, and J. Cambier. Stress‐induced analgesia in human: endogenous opioids and naloxone‐reversible depression of pain reflexes. Science 212: 689–691, 1981.
 878. Willer, J. C., A. Roby, P. Boulu, and D. Albe‐Fessard. Depressive effect of high frequency peripheral conditioning stimulation upon the nociceptive component of the human blink effect. Brain Res. 239: 322–326, 1982.
 879. Williams, J. T., T. M. Egan, and R. A. North. Enkephalin opens potassium channels on mammalian central neurones. Nature London 299: 74–81, 1982.
 880. Williams, J. T., and W. Zieglgänsberger. Mature spinal ganglion cells are not sensitive to opiate receptor mediated actions. Neurosci. Lett. 21: 211–216, 1981.
 881. Williams, J. T., and W. Zieglgänsberger. Neurons in the frontal cortex of rat carry multiple opiate receptors. Brain Res. 226: 304–308, 1981.
 882. Williams, J. T., and W. Zieglgänsberger. The acute effects of capsaicin on rat primary afferents and spinal neurons of the dorsal horn. Brain Res. 253: 125–131, 1982.
 883. Willis, W. D. Control of nociceptive transmission in the spinal cord. In: Progress in Sensory Physiology. Control of Nociceptive Transmission in the Spinal Cord, edited by H. Autrum, D. Ottoson, E. R. Perl, and R. F. Schmidt. Berlin: Springer‐Verlag, 1982, vol. 3.
 884. Willis, W. D. The pain system. The neuronal basis of nociceptive transmission in the mammalian nervous system. In: Pain and Headache, edited by P. L. Gildenberg. Basel: Karger, 1985, vol. 8.
 885. Willis, W. D., and R. E. Coggeshall. Sensory Mechanisms of the Spinal Cord. New York: Plenum, 1978.
 886. Willis, W. D., K. D. Gerhart, W. S. Willcockson, R. P. Yezierski, T. K. Wilcox, and C. L. Cargill. Primate raphe‐ and reticulospinal neurons: effects of stimulation in periaqueductal gray or VPLc thalamic nucleus. J. Neurophysiol. 51: 467–480, 1984.
 887. Willis, W. D., L. H. Haber, and R. F. Martin. Inhibition of spinothalamic tract cells and interneurons by brain stem stimulation in the monkey. J. Neurophysiol. 40: 968–981, 1977.
 888. Willis, W. D., D. R. Kenshalo, Jr., and R. B. Leonard. The cells of origin of the primate spinothalamic tract. J. Comp. Neurol. 188: 543–574, 1979.
 889. Willis, W. D., R. B. Leonhard, and D. R. Kenshalo Jr. Spinothalamic tract neurons in the substantia gelatinosa. Science 202: 986, 1978.
 890. Willis, W. D., D. L. Trevino, J. D. Coulter, and R. A. Maunz. Responses of primate spinothalamic tract neurons to natural stimulation of hindlimb. J. Neurophysiol. 37: 358–372, 1974.
 891. Wilson, P. R., and T. L. Yaksh. Baclofen is antinociceptive in the spinal intrathecal space of animals. Eur. J. Pharmacol. 51: 323–330, 1978.
 892. Wolstencroft, J. H., D. C. West, and J. P. Gent. Actions of morphine and opioid peptides on neurones in the reticular formation, raphe nuclei and the periaqueductal gray. In: Iontophoresis and Transmitter Mechanisms in the Mammalian Central Nervous System, edited by R. W. Ryall and J. S. Kelly. Amsterdam: Elsevier/North‐Holland, 1978, p. 341–343.
 893. Woolf, C. J. Analgesia and hyperalgesia produced in the rat by intrathecal naloxone. Brain Res. 189: 593–597, 1980.
 894. Woolf, C. J. A selective effect of naloxone on heterosynaptic C‐fibre‐mediated inhibitions in the rat dorsal horn. Neurosci. Lett. 45: 169–174, 1984.
 895. Woolf, C. J., G. D. Barrett, D. Mitchell, and R. A. Myers. Naloxone‐reversible peripheral electroanalgesia in intact and spinal rats. Eur. J. Pharmacol. 45: 311–314, 1977
 896. Woolf, C. J., and M. Fitzgerald. Do opioid peptides mediate a presynaptic control of C‐fiber transmission in the rat spinal cord? Neurosci. Lett. 29: 67–72, 1982.
 897. Woolf, C. J., and M. Fitzgerald. The properties of neurones recorded in the superficial dorsal horn of the rat spinal cord. J. Comp. Neurol. 221: 313–328, 1983.
 898. Woolf, C. J., D. Mitchell, and G. D. Barrett. Antinociceptive effects of peripheral segmental stimulation in the rat. Pain 8: 237–252, 1980.
 899. Woolf, C. J., and P. D. Wall. Chronic peripheral nerve section diminishes the primary afferent A‐fibre mediated inhibition of rat dorsal horn neurons. Brain Res. 242: 77–85, 1982.
 900. Wright, D. M., and M. H. T. Roberts. Response of spinal neurones to a substance P analogue, noxious pinch, and bradykinin. Eur. J. Pharmacol. 64: 165–167, 1980.
 901. Yaksh, T. L. Direct evidence that spinal serotonin and noradrenaline terminals mediate the spinal antinociceptive effects of morphine in the periaqueductal gray. Brain Res. 160: 180–185, 1978.
 902. Yaksh, T. L. Spinal opiate analgesia: characteristics and principles of action. Pain 11: 293–346, 1981.
 903. Yaksh, T. L. Multiple spinal opiate receptor systems in analgesia. In: Advances in Pain Research and Therapy. Neural Mechanisms of Pain, edited by L. Kruger and J. C. Liebeskind. New York: Raven, 1984, vol. 6, p. 197–215.
 904. Yaksh, T. L., E. O. Abay, and V. L. W. Go. Studies on the location and release of cholecystokinin and vasoactive intestinal polypeptide in rat and cat spinal cord. Brain Res. 242: 272–290, 1982.
 905. Yaksh, T. L., J. C. DuChateau, and T. A. Rudy. Antagonism by methysergide and cinanserin of the antinociceptive action of morphine administered into the periaqueductal gray. Brain Res. 104: 367–372, 1976.
 906. Yaksh, T. L., and R. P. Elde. Factors governing release of methionine enkephalin‐like immunoreactivity from mesencephalon and spinal cord of the cat in vivo. J. Neurophysiol. 46: 1056–1075, 1981.
 907. Yaksh, T. L., D. A. Farb, S. E. Leeman, and T. M. Jessell. Intrathecal capsaicin depletes substance P in the rat spinal cord and produces prolonged thermal analgesia. Science 206: 481–483, 1979.
 908. Yaksh, T. L., and D. L. Hammond. Peripheral and central substrates involved in the rostrad transmission of nociceptive information. Pain 13: 1–85, 1982.
 909. Yaksh, T. L., and D. L. Hammond. Putative transmitters of descending systems—studies of local administration and liberation. In: Brain Stem Control of Spinal Mechanism, edited by B. H. Sjölund and A. Björklund Amsterdam: Elsevier, 1982, p. 473–492.
 910. Yaksh, T. L., and J. L. Henry. Antinociceptive effects of intrathecally administered human beta‐endorphin in the rat and cat. Can. J. Physiol. Pharmacol. 56: 754–759, 1978.
 911. Yaksh, T. L., S. P. Huang, T. A. Rudy, and R. C. A. Fredericksen. The direct and specific opiate‐like effect of met5‐enkephalin and analogues on the spinal cord. Neuroscience 2: 593–596, 1977.
 912. Yaksh, T. L., T. M. Jessel, R. Gamse, A. W. Mudge, and S. E. Leeman. Intrathecal morphine inhibits substance P release from mammalian spinal cord in vivo. Nature London 286: 155–156, 1980.
 913. Yaksh, T. L., R. L. Plant, and T. A. Rudy. Studies on the antagonism by raphe lesions of the antinociceptive action of systemic morphine. Eur. J. Pharmacol. 41: 399–408, 1977.
 914. Yaksh, T. L., and S. V. R. Reddy. Studies on the analgetic effects of intrathecal opiates, alpha‐adrenergic agonists and baclofen: their pharmacology in the primate. Anesthesiology 54: 451–467, 1981.
 915. Yaksh, T. L., and T. A. Rudy. Analgesia mediated by a direct spinal action of narcotics. Science 192: 1357–1358, 1976.
 916. Yaksh, T. L., and T. A. Rudy. Studies on the direct spinal action of narcotics in the production of analgesia in the rat. J. Pharmacol. Exp. Ther. 202: 411–428, 1977.
 917. Yaksh, T. L., and T. A. Rudy. Narcotic analgetics: CNS sites and mechanisms of action as revealed by intracerebral injection techniques. Pain 4: 299–359, 1978.
 918. Yaksh, T. L., C. Schmauss, P. E. Micevych, E. O. Abay, and L. W. Go. Pharmacological studies on the application, disposition, and release of neurotensin in the spinal cord. In: Neurotensin, a Brain and Gastrointestinal Peptide, edited by C. B. Nemeroff and A. J. Prange, Jr. New York: NY Acad. Sci., 1982, p. 228–243.
 919. Yaksh, T. L., and G. M. Tyce. Microinjection of morphine into the periaqueductal gray evokes the release of serotonin from the spinal cord. Brain Res. 171: 176–181, 1979.
 920. Yaksh, T. L., and P. R. Wilson. Spinal serotonin terminal system mediates antinociception. J. Pharmacol. Exp. Ther. 208: 446–453, 1979.
 921. Yamamoto, M., F. Kumagai, S. Tachikawa, and H. Maeno. Lack of effect of levallorphan on analgesia induced by intraventricular application of porcine calcitonin in mice. Eur. J. Pharmacol. 55: 211–213, 1979.
 922. Yeung, J. C., and T. A. Rudy. Sites of antinociceptive action of systemically injected morphine: involvement of supraspinal loci as revealed by intracerebroventricular injections of naloxone. J. Pharmacol. Exp. Ther. 215: 626–632, 1980.
 923. Yeung, J. C., T. L. Yaksh, and T. A. Rudy. Concurrent mapping of brain sites for sensitivity to the direct application of morphine and focal electrical stimulation in the production of antinociception in the rat. Pain 4: 23–40, 1977.
 924. Yezierski, R. P., K. D. Gerhart, B. J. Schrock, and W. D. Willis. A further examination of effects of cortical stimulation on primate spinothalamic tract cells. J. Neurophysiol. 49: 424–441, 1983.
 925. Yezierski, R. P., T. K. Wilcox, and W. D. Willis. The effects of serotonin antagonists on the inhibition of primate spinothalamic tract cells produced by stimulation in nucleus raphe magnus or the periaqueductal gray. J. Pharmacol. Exp. Ther. 220: 266–277, 1982.
 926. Yi, C. C., T. H. Lu, S. H. Wu, and K. Tsou. A study of the release of 3H‐5‐hydroxytryptamine from brain during acupuncture and morphine analgesia. Sci. Sin. 20: 113–124, 1977.
 927. Yokota, T., and S. Hashimoto. Periaqueductal gray and tooth pulp afferent interaction on units in caudal medulla oblongata. Brain Res. 117: 508–512, 1976.
 928. Yokota, T., and N. Matsumoto. Location and functional organization of trigeminal wide dynamic range neurons within the nucleus ventralis posteromedialis of the cat. Neurosci. Lett. 39: 231–236, 1983.
 929. Yoshimura, M., and R. A. North. Substantia gelatinosa neurones hyperpolarised in vitro by enkephalin. Nature London 305: 529–530, 1983.
 930. Young, A. B., and R. L. Macdonald. Glycine as a spinal cord neurotransmitter. In: Handbook of the Spinal Cord. Pharmacology, edited by R. A. Davidoff. New York: Dekker, 1983, vol. 1, p. 1–43.
 931. Young, W. S., III, and M. J. Kuhar. Noradrenergic alpha 1 and alpha 2 receptors: light microscopic autoradiographic localization. Proc. Natl. Acad. Sci. USA 77: 1696–1700, 1980.
 932. Young, W. S., III, G. R. Uhl, and M. J. Kuhar. Iontophoresis of neurotensin in area of the locus coeruleus. Brain Res. 150: 431–435, 1978.
 933. Zemlan, F. P., S. A. Corrigan, and D. W. Pfaff. Noradrenergic and serotonergic mediation of spinal analgesia mechanisms. Eur. J. Pharmacol. 61: 111–124, 1980.
 934. Zetler, G. Analgesia and ptosis caused by caerulein and cholecystokinin octapeptide (CCK‐8). Neuropharmacology 19: 415–422, 1980.
 935. Zhang, A., X. Pan, S. Xu, J. Cheng, and W. Mo. Endorphins and acupuncture analgesia. Chin. Med. J. 93: 673–680, 1980.
 936. Zieglgänsberger, W. Actions of amino acids, amines and neuropeptides on target cells in the mammalian central nervous system. In: Progress in Brain Research. Chemical Transmission in the Brain, edited by R. M. Buijs, P. Pevét, and D. F. Swaab. Amsterdam: Elsevier, 1982, vol. 55, p. 297–320.
 937. Zieglgänsberger, W. Opioid actions on mammalian spinal neurons. Int. Rev. Neurobiol. 25: 243–275, 1984.
 938. Zieglgänsberger, W., and H. Bayerl. The mechanism of inhibition of neuronal activity by opiates in the spinal cord of the cat. Brain Res. 115: 111–128, 1976.
 939. Zieglgänsberger, W., E. French, N. Mercuri, F. Pelayo, and J. Williams. Multiple opiate receptors on neurons in the mammalian central nervous system. In vivo and in vitro studies. Life Sci. 31: 2343–2346, 1982.
 940. Zieglgänsberger, W., E. D. French, G. R. Siggins, and F. E. Bloom. Opioid peptides may excite hippocampal pyramidal neurons by inhibiting adjacent inhibitory interneurons. Science 205: 415–417, 1979.
 941. Zieglgänsberger, W., and J. Fry. Actions of opioids on single neurons. In: Developments in Opiate Research, edited by A. Herz. New York: Dekker, 1978, p. 193–239.
 942. Zieglgänsberger, W., and J. P. Fry, A. Herz, L. Moroder, and E. Wünsch. Enkephalin‐induced inhibition of cortical neurones and the lack of this effect in morphine tolerant/dependent rats. Brain Res. 115: 160–164, 1976.
 943. Zieglgänsberger, W., and A. Herz. Changes of cutaneous receptive fields of spino‐cervical‐tract neurons and other dorsal horn neurons by microelectrophoretically administered amino acids. Exp. Brain Res. 13: 111–126, 1971.
 944. Zieglgänsberger, W., and E. A. Puil. Actions of glutamic acid on spinal neurons. Exp. Brain Res. 17: 35–49, 1973.
 945. Zieglgänsberger, W., and B. Sutor. Responses of substantia gelatinosa neurons to putative neurotransmitters in an in vitro preparation of the adult rat spinal cord. Brain Res. 279: 316–320, 1983.
 946. Zieglgänsberger, W., and B. Sutor. Opioid peptides depress neuronal activity of neocortical neurons in vitro by reduction of excitatory input (Abstract). Naunyn‐Schmiedeberg's Arch. Pharmacol. 325, Suppl.: R72, 1984.
 947. Zieglgänsberger, W., and I. F. Tulloch. Effects of substance P on neurones in the dorsal horn of the spinal cord of the cat. Brain Res. 166: 273–282, 1979.
 948. Zieglgänsberger, W., and I. F. Tulloch. The effects of methionine‐ and leucine‐enkephalin on spinal neurones of the cat. Brain Res. 167: 53–64, 1979.
 949. Zimmermann, M. Neurophysiology of nociception. In: Neurophysiology II, edited by R. Porter. Baltimore, MD: University Park, 1976, vol. 10, p. 179–221. (Int. Rev. Physiol. Ser.)
 950. Zorman, G., G. Belcher, J. E. Adams, and H. L. Fields. Lumbar intrathecal naloxone blocks analgesia produced by microstimulation of the ventromedial medulla in the rat. Brain Res. 236: 77–84, 1982.
 951. Zorman, G., I. D. Hentall, J. E. Adams, and H. L. Fields. Naloxone‐reversible analgesia produced by microstimulation in the rat medulla. Brain Res. 219: 137–148, 1981.
 952. Zukin, R. S., and S. R. Zukin. The case of multiple opiate receptors. Trends Neurosci. 7: 160–164, 1984.

Contact Editor

Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite

Walter Zieglgänsberger. Central Control of Nociception. Compr Physiol 2011, Supplement 4: Handbook of Physiology, The Nervous System, Intrinsic Regulatory Systems of the Brain: 581-645. First published in print 1986. doi: 10.1002/cphy.cp010411