Activity Of Spinal Dorsal Horn Neurons Research Articles

Amygdala group II mGluRs mediate the inhibitory effects of systemic group II mGluR activation on behavior and spinal neurons in a rat model of arthritis pain

The amygdala plays a critical role in emotional-affective aspects of behaviors and pain modulation. The central nucleus of amygdala (CeA) serves major output functions, and neuroplasticity in the CeA is linked to pain-related behaviors in different models. Activation of Gi/o-coupled group II metabotropic glutamate receptors (mGluRs), which consist of mGluR2 and mGluR3, can decrease neurotransmitter release and regulate synaptic plasticity. Group II mGluRs have emerged as targets for neuropsychiatric disorders and can inhibit pain-related processing and behaviors. Surprisingly, site and mechanism of antinociceptive actions of systemically applied group II mGluR agonists are not clear. Our previous work showed that group II mGluR activation in the amygdala inhibits pain-related CeA activity, but behavioral and spinal consequences remain to be determined. Here we studied the contribution of group II mGluRs in the amygdala to the antinociceptive effects of a systemically applied group II mGluR agonist (LY379268) on behavior and spinal dorsal horn neuronal activity, using the kaolin/carrageenan-induced knee joint arthritis pain model. Audible and ultrasonic vocalizations (emotional responses) and mechanical reflex thresholds were measured in adult rats with and without arthritis (5–6 h postinduction). Extracellular single-unit recordings were made from spinal dorsal horn wide dynamic range neurons of anesthetized (isoflurane) rats with and without arthritis (5–6 h postinduction). Systemic (intraperitoneal) application of a group II mGluR agonist (LY379268) decreased behaviors and activity of spinal neurons in the arthritis pain model but not under normal conditions. Stereotaxic administration of LY379268 into the CeA mimicked the effects of systemic application. Conversely, stereotaxic administration of a group II mGluR antagonist (LY341495) into the CeA reversed the effects of systemic application of LY379268 on behaviors and dorsal horn neuronal activity in arthritic rats. The data show for the first time that the amygdala is the critical site of action for the antinociceptive behavioral and spinal neuronal effects of systemically applied group II mGluR agonists.

Deep Tissue Incision Enhances Spinal Dorsal Horn Neuron Activity During Static Isometric Muscle Contraction in Rats

Translational correlates to pain with activities after deep tissue injury have been rarely studied. We hypothesized that deep tissue incision causes greater activation of nociception-transmitting neurons evoked by muscle contraction. In vivo neuronal activity was recorded in 203 dorsal horn neurons (DHNs) from 97 rats after sham, skin-only, or skin + deep muscle incision. We evaluated DHN responses to static, isometric muscle contractions induced by direct electrical stimulation of the muscle. The effect of pancuronium on DHN response to contractions was also examined. Approximately 50% of DHNs with receptive fields in the hindpaw were excited during muscle contraction. One-second .5- and 1.0-g muscle contractions produced greater DHN activity after skin + deep muscle incision (median [interquartile range], 32 [5–39] impulses, P = .021; and 36 [26–46] impulses, P = .006, respectively) than after sham (6 [0–21] and 15 [8–32] impulses, respectively). Neuromuscular blockade with pancuronium inhibited the muscle contractions and DHN activation during electrical stimulation, demonstrating contraction-induced activation. The greater response of spinal DHNs to static muscle contraction after skin + deep muscle incision may model and inform mechanisms of dynamic pain after surgery. PerspectiveCompletion of various activities is an important milestone for recovery and hospital discharge after surgery. Skin + deep muscle incision caused greater activation of nociception-transmitting DHNs evoked by muscle contraction compared with skin-only incision. This result suggests an important contribution of deep muscle injury to activity-evoked hyperalgesia after surgery.

Hydrogen Peroxide Induces Muscle Nociception via Transient Receptor Potential Ankyrin 1 Receptors.

H2O2 has a variety of actions in skin wounds but has been rarely studied in deep muscle tissue. Based on response to the transient receptor potential ankyrin 1 antagonists after plantar incision, we hypothesized that H2O2 exerts nociceptive effects via the transient receptor potential ankyrin 1 in muscle. Nociceptive behaviors in rats (n = 269) and mice (n = 16) were evaluated after various concentrations and volumes of H2O2 were injected into the gastrocnemius muscle or subcutaneous tissue. The effects of H2O2 on in vivo spinal dorsal horn neuronal activity and lumbar dorsal root ganglia neurons in vitro were evaluated from 26 rats and 6 mice. Intramuscular (mean ± SD: 1,436 ± 513 s) but not subcutaneous (40 ± 58 s) injection of H2O2 (100 mM, 0.6 ml) increased nociceptive time. Conditioned place aversion was evident after intramuscular (-143 ± 81 s) but not subcutaneous (-2 ± 111 s) injection of H2O2. These H2O2-induced behaviors were blocked by transient receptor potential ankyrin 1 antagonists. Intramuscular injection of H2O2 caused sustained in vivo activity of dorsal horn neurons, and H2O2 activated a subset of dorsal root ganglia neurons in vitro. Capsaicin nerve block decreased guarding after plantar incision and reduced nociceptive time after intramuscular H2O2. Nociceptive time after intramuscular H2O2 in transient receptor potential ankyrin 1 knockout mice was shorter (173 ± 156 s) compared with wild-type mice (931 ± 629 s). The greater response of muscle tissue to H2O2 may help explain why incision that includes deep muscle but not skin incision alone produces spontaneous activity in nociceptive pathways.

The medullary dorsal reticular nucleus as a relay for descending pronociception induced by the mGluR5 in the rat infralimbic cortex

Metabotropic glutamate receptor 5 (mGluR5) activation in the infralimbic cortex (IL) induces pronociceptive behavior in healthy and monoarthritic rats. Here we studied whether the medullary dorsal reticular nucleus (DRt) and the spinal TRPV1 are mediating the IL/mGluR5-induced spinal pronociception and whether the facilitation of pain behavior is correlated with changes in spinal dorsal horn neuron activity. For drug administrations, all animals had a cannula in the IL as well as a cannula in the DRt or an intrathecal catheter. Heat-evoked paw withdrawal was used to assess pain behavior in awake animals. Spontaneous and heat-evoked discharge rates of single DRt neurons or spinal dorsal horn wide-dynamic range (WDR) and nociceptive-specific (NS) neurons were evaluated in lightly anesthetized animals.Activation of the IL/mGluR5 facilitated nociceptive behavior in both healthy and monoarthritic animals, and this effect was blocked by lidocaine or GABA receptor agonists in the DRt. IL/mGluR5 activation increased spontaneous and heat–evoked DRt discharge rates in healthy but not monoarthritic rats. In the spinal dorsal horn, IL/mGluR5 activation increased spontaneous activity of WDR neurons in healthy animals only, whereas heat-evoked responses of WDR and NS neurons were increased in both experimental groups. Intrathecally administered TRPV1 antagonist prevented the IL/mGluR5-induced pronociception in both healthy and monoarthritic rats.The results suggest that the DRt is involved in relaying the IL/mGluR5-induced spinal pronociception in healthy control but not monoarthritic animals. Spinally, the IL/mGluR5-induced behavioral heat hyperalgesia is mediated by TRPV1 and associated with facilitated heat-evoked responses of WDR and NS neurons.

Stimulation of the ventral tegmental area increased nociceptive thresholds and decreased spinal dorsal horn neuronal activity in rat.

Deep brain stimulation has been found to be effective in relieving intractable pain. The ventral tegmental area (VTA) plays a role not only in the reward process, but also in the modulation of nociception. Lesions of VTA result in increased pain thresholds and exacerbate pain in several pain models. It is hypothesized that direct activation of VTA will reduce pain experience. In this study, we investigated the effect of direct electrical stimulation of the VTA on mechanical, thermal and carrageenan-induced chemical nociceptive thresholds in Sprague-Dawley rats using our custom-designed wireless stimulator. We found that: (1) VTA stimulation itself did not show any change in mechanical or thermal threshold; and (2) the decreased mechanical and thermal thresholds induced by carrageenan injection in the hind paw contralateral to the stimulation site were significantly reversed by VTA stimulation. To further explore the underlying mechanism of VTA stimulation-induced analgesia, spinal cord dorsal horn neuronal responses to graded mechanical stimuli were recorded. VTA stimulation significantly inhibited dorsal horn neuronal activity in response to pressure and pinch from the paw, but not brush. This indicated that VTA stimulation may have exerted its analgesic effect via descending modulatory pain pathways, possibly through its connections with brain stem structures and cerebral cortex areas.

Neuronal hyperexcitability in the dorsal horn after painful facet joint injury

Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6–C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7days after joint loading. Extracellular recordings of spinal dorsal horn neuronal activity between C6 and C8 (117 neurons) were obtained from anesthetized rats, with both painful and non-painful behavioral outcomes established by the magnitude of capsule stretch. The frequency of neuronal firing during noxious pinch (p<0.0182) and von Frey filaments applications (4–26g) to the forepaw was increased (p<0.0156) in the painful group compared to the non-painful and sham groups. In addition, the incidence and frequency of spontaneous and after discharge firing were greater in the painful group (p<0.0307) relative to sham. The proportion of cells in the deep laminae that responded as wide dynamic range neurons also was increased in the painful group relative to non-painful or sham groups (p<0.0348). These findings suggest that excessive facet capsule stretch, while not producing visible tearing, can produce functional plasticity of dorsal horn neuronal activity. The increase in neuronal firing across a range of stimulus magnitudes observed at day 7 post-injury provides the first direct evidence of neuronal modulation in the spinal cord following facet joint loading, and suggests that facet-mediated chronic pain following whiplash injury is driven, at least in part, by central sensitization.

Peripheral Nerve Injury–Induced Changes in Spinal α2-Adrenoceptor–Mediated Modulation of Mechanically Evoked Dorsal Horn Neuronal Responses

Peripheral nerve injury has been associated with changes in the modulatory action of noradrenergic pathways on nociceptive traffic through the spinal cord. Thus, the purpose of this study was to assess whether endogenous noradrenergic descending inhibition, acting via spinal alpha(2)-receptors, is altered after peripheral nerve damage. We investigated the effects of spinal administration of a selective alpha(2)-adrenoceptor antagonist, atipamezole, on the evoked activity of deep dorsal horn neurons in animals with selective spinal nerve ligation (SNL) compared with a sham-operated group. Intrathecal administration of atipamezole (1, 10, and 100 microg) did not produce any significant effects on the electrically evoked neuronal responses in either animal group, with the exception of a small but significant enhancement of the postdischarge in the sham control group only. Similarly, no significant effects were observed with the heat-evoked neuronal responses in either group. Interestingly, atipamezole significantly increased the evoked responses of neurons to low-intensity mechanical stimuli in the sham control group but was without effect in the SNL group. Thus, our findings suggest that peripheral nerve injury can result in the suppression of noradrenergic spinal alpha(2)-adrenoceptor-mediated inhibition of spinal dorsal horn neuronal activity evoked by low-intensity mechanical stimuli. These results suggest that a tonically active noradrenergic inhibition of mechanically evoked spinal dorsal horn neuronal responses is lost after nerve injury. This shift in the balance of noradrenergic controls may be one of the many underlying mechanisms by which behavioral symptoms of hypersensitivity develop after nerve damage.

Superficial NK1 expressing spinal dorsal horn neurones modulate inhibitory neurotransmission mediated by spinal GABAA receptors

Lamina 1 projection neurones which express the NK1 receptor (NK1R+) drive a descending serotonergic pathway from the brainstem that enhances spinal dorsal horn neuronal activity via the facilitatory spinal 5-HT3 receptor. Selective destruction of these cells via lumbar injection of substance P-saporin (SP-SAP) attenuates pain behaviours, including mechanical and thermal hypersensitivity, which are mirrored by deficits in the evoked responses of lamina V-VI wide dynamic range (WDR) neurones to noxious stimuli. To assess whether removing the origin of this facilitatory spino-bulbo-spinal loop results in alterations in GABAergic spinal inhibitory systems, the effects of spinal bicuculline, a selective GABA(A) receptor antagonist, on the evoked neuronal responses to electrical (Abeta-, Adelta-, C-fibre, post-discharge and Input) and mechanical (brush, prod and von Frey (vF) 8 and 26 g) stimuli were measured in SAP and SP-SAP groups. In the SAP control group, bicuculline produced a significant dose related facilitation of the electrically evoked Adelta-, C-fibre, post-discharge and input neuronal responses. The evoked mechanical (prod, vF8 g and 26 g) responses were also significantly increased. Brush evoked neuronal responses in these animals were enhanced but did not reach significance. This facilitatory effect of bicuculline, however, was lost in the SP-SAP treated group. The generation of intrinsic GABAergic transmission in the spinal cord appears dependent on NK1 bearing neurons, yet despite the loss of GABAergic inhibitory controls after SP-SAP treatment, the net effect is a decrease in spinal cord excitability. Thus activation of these cells predominantly drives facilitation.

Electrical stimulation of the primary somatosensory cortex inhibits spinal dorsal horn neuron activity

Cortical stimulation has been demonstrated to alleviate certain pain conditions. The aim of this study was to determine the responses of the spinal cord dorsal horn neurons to stimulation of the primary somatosensory cortex (SSC). We hypothesized that direct stimulation of the SSC will inhibit the activity of spinal dorsal horn neurons by activating the descending inhibitory system. Thirty-four wide dynamic range spinal dorsal horn neurons were recorded in response to graded mechanical stimulation (brush, pressure, and pinch) at their respective receptive fields while a stepwise electrical stimulation (300 Hz, 0.1 ms, at 10, 20, and 30 V) was applied in the SSC through a bipolar tungsten electrode. The responses to brush at control, 10 V, 20 V, 30 V, and recovery were 16.0 ± 2.3, 15.8 ± 2.2, 14.6 ± 1.8, 14.8 ± 2.0, and 17.0 ± 2.2 spikes/s, respectively. The responses to pressure at control, 10 V, 20 V, 30 V, and recovery were 44.7 ± 5.5, 37.0 ± 5.6, 29.5 ± 4.8, 31.6 ± 5.2, and 43.2 ± 5.7 spikes/s, respectively. The responses to pinch at control, 10 V, 20 V, 30 V, and recovery were 58.1 ± 7.0, 42.9 ± 5.5, 34.8 ± 3.9, 34.6 ± 4.4, and 52.6 ± 6.0 spikes/s, respectively. Significant decreases of the dorsal horn neuronal responses to pressure and pinch were observed during SSC stimulation. It is concluded that electrical stimulation of the SSC produces transient inhibition of the responses of spinal cord dorsal horn neurons to higher intensity mechanical stimuli without affecting innocuous stimuli.

Spinal dorsal horn neuron response to mechanical stimuli is decreased by electrical stimulation of the primary motor cortex

Motor cortex stimulation (MCS) has been used clinically as a tool for the control for central post-stroke pain and neuropathic facial pain. The underlying mechanisms involved in the antinociceptive effect of MCS are not clearly understood. We hypothesize that the antinociceptive effect is through the modulation of the spinal dorsal horn neuron activity. Thirty-two wide dynamic range spinal dorsal horn neurons were recorded, in response to graded mechanical stimulation (brush, pressure, and pinch) at their respective receptive fields, while a stepwise electrical stimulation was applied simultaneously in the motor cortex. The responses to brush at control, 10 V, 20 V, and 30 V, and recovery were 11.5 ± 1.6, 12.1 ± 2.6, 11.1 ± 2.2, 10.5 ± 2.1, and 13.2 ± 2.5 spikes/s, respectively. The responses to pressure at control, 10 V, 20 V, and 30 V, and recovery were 33.2 ± 6.1, 22.9 ± 5.3, 20.5 ± 5.0, 17.3 ± 3.8, and 27.0 ± 4.0 spikes/s, respectively. The responses to pinch at control, 10 V, 20 V, and 30 V, and recovery were 37.2 ± 6.4, 26.3 ± 4.7, 25.9 ± 4.7, 22.5 ± 4.3, and 35.0 ± 6.2 spikes/s, respectively. It is concluded that, in the rat, electrical stimulation of the motor cortex produces significant transient inhibition of the responses of spinal cord dorsal horn neurons to higher intensity mechanical stimuli without affecting their response to an innocuous stimulus.

Suppressive effect of spinal dorsal-horn neuronal activity by local spinal-cord cooling is reversed by naloxone in cats.

The purpose of this study was to assess the effect of local spinal cord cooling on spinal dorsal-horn neuronal activity, with special emphasis on the role of endogenous opioid. Decerebrate, spinal-cord-transected cats ( n= 30) were subjected to local spinal-cord irrigation, using 0.9 N saline solution (15 degrees C; n= 15, and 35 degrees C; n= 15) for 90 min. The extracellular, single-cell activity of spinal dorsal-horn neurons responding to noxious stimulation was recorded. Sixty-one minutes after induction of local spinal-cord irrigation, naloxone (0.1 mg.kg(-1)) was administered intravenously. Local spinal-cord blood flow was measured using the hydrogen clearance technique. Local spinal cord cooling produced significant suppression of both spontaneous and evoked activity (33.1 +/- 7.7% and 31.4 +/- 5.5%, respectively; mean +/- SE). Naloxone reversed this suppression immediately. Local spinal-cord blood flow was significantly reduced during spinal-cord cooling, but naloxone did not change local spinal-cord blood flow. The results demonstrate that endogenous opioids may play an important role in dorsal-horn neuronal suppression induced by local spinal-cord cooling.

Spinal R-phenyl-isopropyl adenosine inhibits spinal dorsal horn neurons responding to noxious heat stimulation in the absence and presence of sensitization

The effects of spinally administered R(−) N 6-(2-phenylisopropyl) adenosine (R-PIA) on spinal dorsal horn neurons were investigated in anesthetized rats. Extracellular, single-unit recordings were measured during noxious heating of receptive fields on the hind paw. Three series of experiments were carried out to characterize the effects of R-PIA on spinal dorsal horn neuronal activity. In the first set of experiments, R-PIA dose-dependently suppressed noxiously evoked activity of spinal dorsal horn neurons. In the second set of experiments, R-PIA suppressed noxiously evoked activity in neurons sensitized by the topical application of mustard oil to a region of skin adjacent to their receptive fields. In the third set of experiments, R-PIA prevented mustard oil induced sensitization of dorsal horn neurons. In all cases, the adenosine receptor antagonist theophylline reversed the action of R-PIA. The results of these investigations indicate the involvement of spinal adenosine receptors in spinal pathways of central sensitization and in the modulation of somatically induced noxious pain.

Tonic 5-HT modulation of spinal dorsal horn neuron activity evoked by both noxious and non-noxious stimuli: a source of neuronal plasticity

The influence of tonic serotonergic modulation on the responses of spinal dorsal horn neurons to natural peripheral stimulation was examined in physiologically intact, awake, drug-free cats. Systemically administered methysergide (maximum cumulative dose 2 mg/kg) caused significant changes in responses of some dorsal horn neurons to both mildly noxious and non-noxious stimulation. Individual changes provide evidence, in this model, for tonic 5-HT modulation of many aspects of sensory transmission at the level of the spinal cord. Taken together, the changes demonstrate the significant degree of plasticity that exists for some spinal dorsal horn neurons. It is clear that the plasticity of some spinal dorsal horn neurons allows for a much broader response profile than would be apparent under the restricted circumstances of a normal neurophysiologic study. Removal of tonic inhibition on responses to noxious stimuli may be an aspect of neuronal plasticity that functions to provide an immediate change in the way that the nervous system responds to a noxious stimulus.

Functional organization of the cat's dorsal horn: connectivity of myelinated fiber systems of hairy skin.

Functional organization of the cat's dorsal horn: connectivity of myelinated fiber systems of hairy skin.D N Tapper, P B Brown, and H MoraffD N Tapper, P B Brown, and H MoraffPublished Online:01 Sep 1973https://doi.org/10.1152/jn.1973.36.5.817MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByLocal Circuit Connections Between Hamster Laminae III and IV Dorsal Horn NeuronsStephen P. Schneider1 March 2008 | Journal of Neurophysiology, Vol. 99, No. 3Mechanosensory afferent input and neuronal firing properties in rodent spinal laminae III–V: re-examination of relationships with analysis of responses to static and time-varying stimuliBrain Research, Vol. 1034, No. 1-2Modulation of synaptic transmission from segmental afferents by spontaneous activity of dorsal horn spinal neurones in the cat12 August 2004 | The Journal of Physiology, Vol. 529, No. 2Tonic 5-HT modulation of spinal dorsal horn neuron activity evoked by both noxious and non-noxious stimuli: a source of neuronal plasticityPain, Vol. 40, No. 2A hypothesis on the physiological basis for causalgia and related painsPain, Vol. 24, No. 3Parallel processing of somatosensory information: A theoryBrain Research Reviews, Vol. 6, No. 1Innervation patterns of cutaneous hair receptors in catBrain Research, Vol. 249, No. 2The responses of dorsal horn neurones to controlled mechanical stimulation of the hindlimb skin in the rabbitBrain Research Reviews, Vol. 4, No. 1NociceptionBrain Research, Vol. 99, No. 2Spinal cord coding of graded nonnoxious and noxious temperature increasesExperimental Neurology, Vol. 48, No. 2Segmental and supraspinal actions on dorsal horn neurons responding to noxious and non-noxious skin stimuliPain, Vol. 1, No. 2Myelinated fiber types in the superficial radial nerve of the cat and their central projectionsBrain Research, Vol. 78, No. 1Afferent fibers with multiple encoding sitesBrain Research, Vol. 77, No. 2 More from this issue > Volume 36Issue 5September 1973Pages 817-26 https://doi.org/10.1152/jn.1973.36.5.817PubMed4805013History Published online 1 September 1973 Published in print 1 September 1973 Metrics

Functional organization of the cat's dorsal horn: spontaneous activity and central cell response to single impulses in single type I fibers.

Functional organization of the cat's dorsal horn: spontaneous activity and central cell response to single impulses in single type I fibers.P B Brown, H Moraff, and D N TapperP B Brown, H Moraff, and D N TapperPublished Online:01 Sep 1973https://doi.org/10.1152/jn.1973.36.5.827MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMechanosensory afferent input and neuronal firing properties in rodent spinal laminae III–V: re-examination of relationships with analysis of responses to static and time-varying stimuliBrain Research, Vol. 1034, No. 1-2Interlimb reflex activity after spinal cord injury in man: strengthening response patterns are consistent with ongoing synaptic plasticityClinical Neurophysiology, Vol. 116, No. 1From innervation density to tactile acuityBrain Research, Vol. 1011, No. 1Effects of spinal and peripheral nerve lesions on the intersegmental synchronization of the spontaneous activity of dorsal horn neurons in the cat lumbosacral spinal cordNeuroscience Letters, Vol. 361, No. 1-3Synaptic transmission between single tactile and kinaesthetic sensory nerve fibers and their central target neuronesBehavioural Brain Research, Vol. 135, No. 1-2Modulation of synaptic transmission from segmental afferents by spontaneous activity of dorsal horn spinal neurones in the cat12 August 2004 | The Journal of Physiology, Vol. 529, No. 2Correlation of Peripheral Innervation Density and Dorsal Horn Map ScaleLei Wang, Ronald Millecchia, and Paul B. Brown1 August 1997 | Journal of Neurophysiology, Vol. 78, No. 2Tonic 5-HT modulation of spinal dorsal horn neuron activity evoked by both noxious and non-noxious stimuli: a source of neuronal plasticityPain, Vol. 40, No. 2Lack of spontaneous activity of cutaneous spinal dorsal horn neurons in awake, drug-free, spinally transected catsExperimental Neurology, Vol. 96, No. 2Electrical stimulation reveals relatively ineffective sural nerve projections to dorsal horn neurons in the catBrain Research, Vol. 371, No. 1Anatomical changes in cat dorsal horn cells after transection of a single dorsal rootExperimental Neurology, Vol. 64, No. 3The effect of dorsal column stimulation on the nociceptive response of dorsal horn cells and its relevance for pain suppressionPain, Vol. 4, No. Supp CGeneration of spike trains in CNS neuronsBrain Research, Vol. 84, No. 1Myelinated fiber types in the superficial radial nerve of the cat and their central projectionsBrain Research, Vol. 78, No. 1 More from this issue > Volume 36Issue 5September 1973Pages 827-39 https://doi.org/10.1152/jn.1973.36.5.827PubMed4375707History Published online 1 September 1973 Published in print 1 September 1973 Metrics