Medial bulboreticular response to peripherally applied noxious stimuli

LeBlanc, Hector J.; Gatipon, Glenn B.

doi:10.1016/0014-4886(74)90024-7

Cited by 62 publications

(11 citation statements)

References 22 publications

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“…2006). In fact, a majority of cells in the NRGc region, including reticulospinal neurones, respond to noxious peripheral stimuli (Wolstencroft, 1964; Casey, 1969; Leblanc & Gatipon, 1974), and electrical stimulation in this same NRGc region evokes aversive behaviour in awake cats (Casey, 1971). The question then arises as to whether SRD cells influence the activity of NRGc reticulospinal neurones responding to noxious input.…”

Section: Discussionmentioning

confidence: 99%

Intracellular recordings of subnucleus reticularis dorsalis neurones revealed novel electrophysiological properties and windup mechanisms

Jorge-Soto

Canedo

2011

The Journal of Physiology

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Non-technical summary The electrophysiological properties of subnucleus reticularis dorsalis (SRD) neurones were intracellularly studied. The work describes three different classes of cells differentiated by the absence (class I) or presence (classes II and III) of a fast postspike hyperpolarisation followed by depolarising sags and activation of low threshold calcium channels (class II) or type A potassium channels (class III); properties that entitle the different SRD cells to intrinsically regulate their temporal firing. All three classes showed subthreshold oscillatory activity leading to cumulative excitation (windup) in response to low frequency C-fibre afferent input as well as to low frequency injection of depolarising currents, thus allowing SRD cells to generate windup intrinsically. The three neuronal classes sent collateral branches to the nucleus reticularis gigantocellularis (NRGc) and the spinal cord which would provide simultaneous regulation of pain-related motor responses through the NRGc, and ascending nociceptive information via the SRD-descending fibres ending at the spinal dorsal horn.Abstract Aδ-and/or C-fibre nociceptive inputs drive subnucleus reticularis dorsalis (SRD) neurones projecting to a variety of regions including the spinal cord and the nucleus reticularis gigantocellularis (NRGc), but their electrophysiological properties are largely unknown. Here we intracellularly recorded the SRD neuronal responses to injection of polarising current pulses as well as to electrical stimulation of the cervical spinal posterior quadrant (PQ) and the NRGc. Three different classes of neurones with distinct electrophysiological properties were found: type I were characterised by the absence of a fast postspike hyperpolarisation, type II by the presence of a postspike hyperpolarisation followed by a depolarisation resembling low threshold calcium spikes (LTSs), and type III (lacking LTSs) had a fast postspike hyperpolarisation deinactivating A-like potassium channels leading to enlarged interspike intervals. All three classes generated depolarising sags to hyperpolarising current pulses and showed 3-4.5 Hz subthreshold oscillatory activity leading to windup when intracellularly injecting low-frequency repetitive depolarising pulses as well as in response to 0.5-2 Hz NRGc and PQ electrical stimulation. About half of the 132 sampled neurones responded antidromically to NRGc stimulation with more than 65% of the NRGc-antidromic cells, pertaining to all three types, also responding antidromically to PQ stimulation. NRGc stimulation induced exclusively excitatory first-synaptic-responses whilst PQ stimulation induced first-response excitation in most cases, but inhibitory postsynaptic potentials in a few type II and type III neurones not projecting to the spinal cord that also displayed cumulative inhibitory effects (inverse windup). The results show that SRD cells (i) can actively regulate different temporal firing patterns due to their intrinsic electrophysiological properties, (ii) generate windup u...

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Section: Discussionmentioning

confidence: 99%

Intracellular recordings of subnucleus reticularis dorsalis neurones revealed novel electrophysiological properties and windup mechanisms

Jorge-Soto

Canedo

2011

The Journal of Physiology

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“…Dahlstrom & Fuxe, 1965a, b;Basbaum, Clanton & Fields, 1978;Basbaum & Fields, 1979). Single unit recording reveals that supraspinal units in many of the structures giving rise to the descending systems may be excited by somatic stimulation (Benjamin, 1970;Casey, 1971;Guilbaud, Besson, Oliveras & Wyon-Maillard, 1973;Le Blanc, & Gatipon, 1974). Alternatively, we recognize the possibility that somatic input into higher centres such as the mid line mesencephalon (PAG) or the mid line thalamus, by spinotectal or spinothalamic fibres respectively, could in fact gain access to the descending nuclei via the extensive reciprocal pathways which are known to exist between the mid line diencephalon and central grey (Hamilton, 1973), and central grey and the mid line raphe nuclei (Ruda, 1975).…”

Section: Discussionmentioning

confidence: 99%

Monoamine release from cat spinal cord by somatic stimuli: an intrinsic modulatory system.

Tyce¹,

Yaksh²

1981

The Journal of Physiology

156

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SUMMARY1. Superfusates taken from spinal cords of cats anaesthetized with chloralose and urethane were assayed for endogenous serotonin and noradrenaline by high-pressure liquid chromatography with electrochemical detection.2. Stimulating the dorsolateral funiculus, caudal to a spinal transaction, enhanced in a frequency-dependent manner the levels of monoamines in the spinal superfusate.3. Tyramine added to the superfusate enhanced the release of noradrenaline and serotonin. 4. In cats with intact neuraxes, stimulation of the sciatic nerve at high, but not low intensities produced a 2-to 3-fold increase in the levels of monoamines in the spinal superfusate. This evoked monoamine efflux was attenuated by cold block of the cervical spinal cord.5. Stimulation of the infraorbital branch of the trigeminal nerve evoked the release of noradrenaline and serotonin from the lumbar cord in animals with intact neuraxes. Cold block of the cervical cord blocked trigeminal-evoked release of lumbar serotonin and noradrenaline.6. That the monoamine efflux was not due to elevations in blood pressure was indicated by the failure of vasoxyl, an a-agonist producing hypertension, to evoke any changes in spinal monoamine levels. 7. The monoamine release was not dependent upon either an opiate-sensitive link or upon the activation of the sympathetic ganglia, because systemic administration of naloxone (an opiate antagonist) and chlorisondamine (a ganglionic blocking agent) failed to antagonize the evoked release of amines.8. These results suggest the existence of a spinopetal monoamine system which is activated by peripheral stimuli. The modulatory influence associated with increasing monoamine tone in the spinal cord clearly indicated that somatic stimuli may activate a descending monoamine pathway which serves to modulate the magnitude of the ascending sensory message.

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“…The function of these neurons in the modulation of nociception has been well established (Casey, 1971;Gebhart et al, 1983;Gray and Dostrovsky, 1983;Le Blanc and Gatipon, 1974). Neurons in this region are activated by peripheral noxious stimulation (Casey, 1971;LeBlanc and Gatipon, 1974), whereas stimulation of this area has been reported to alter nociceptive transmission (Basbaum and Fields, 1984;Clark and Proudfit, 1991;Fields and Basbaum, 1978;Satoh et al, 1983;Zhou and Gebhart, 1990). In addition, neurons in this medial portion of the rostral ventral medulla have been shown to respond to chemoreceptor input (Miura et al, 1996), project to medullary respiratory neurons, and innervate phrenic motor neurons, suggesting that these neurons are also involved in the regulation of respiration (Dobbins and Feldman, 1994;Ellenberger and Feldman, 1990;Ellenberger et al, 1992;Hadziefendic and Haxhiu, 1999;Holtman and Speck, 1994;Smith et al, 1989).…”

mentioning

confidence: 96%

“…The medial portion of the rostral ventral medulla has been suggested to be involved in the control of a variety of autonomic functions (LeBlanc and Gatipon, 1974;Miura et al, 1996;Yardley et al, 1989). The function of these neurons in the modulation of nociception has been well established (Casey, 1971;Gebhart et al, 1983;Gray and Dostrovsky, 1983;Le Blanc and Gatipon, 1974).…”

mentioning

confidence: 97%

Medullary and spinal cord projections from cardiovascular responsive sites in the rostral ventromedial medulla

Babic

Ciriello

2004

J of Comparative Neurology

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The rostral ventromedial medulla (RVMM) is a sympathoexcitatory area. However, little is known about its efferent projections. In this study, biotinylated dextran amine (BDA) or Phaseolus vulgaris leucoagglutinin (PHA-L) were used to investigate the medullary and spinal cord projections from pressor sites in RVMM. Initially, RVMM was systematically explored in urethane-anesthetized rats using microinjection of L-glutamate for sites that elicited increases in arterial pressure. A pressor area was identified that included the rostral magnocellular reticular and rostral lateral paragigantocellular reticular nuclei. In the second series of experiments, BDA or PHA-L was iontophoretically injected into RVMM pressor sites. Anterograde labeling was observed throughout the brainstem and spinal cord, bilaterally, but with an ipsilateral predominance. Dense labeling was observed within the nucleus of the solitary tract (NTS); the greatest density of labeling was observed in the caudal dorsolateral, medial, and ventrolateral subnuclei. Additionally, light to moderately dense labeling was found within the nucleus substantia gelatinosus and commissural nucleus. In the nucleus ambiguus/ventrolateral medullary (Amb/VLM) region, the density of labeling was greatest in caudal regions. Within Amb, most of the labeling was localized to its external formation. Anterograde labeling was also found throughout the spinal cord. In the thoracolumbar segments, dense axonal labeling was observed within the dorsolateral funiculus. These labeled axons innervated the intermediolateral nucleus and the central autonomic area. Taken together, these data suggest that RVMM neurons elicit increases in sympathetic activity by likely providing a direct excitatory input to spinal sympathetic preganglionic neurons, and by a direct inhibitory input to medullary cardioinhibitory and depressor areas.

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Medial bulboreticular response to peripherally applied noxious stimuli

Cited by 62 publications

References 22 publications

Intracellular recordings of subnucleus reticularis dorsalis neurones revealed novel electrophysiological properties and windup mechanisms

Intracellular recordings of subnucleus reticularis dorsalis neurones revealed novel electrophysiological properties and windup mechanisms

Monoamine release from cat spinal cord by somatic stimuli: an intrinsic modulatory system.

Medullary and spinal cord projections from cardiovascular responsive sites in the rostral ventromedial medulla

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