Reflex responses of motor nuclei of the lumbo-sacral segments of the spinal cord in cats with local tetanus

1964 ◽  
Vol 58 (2) ◽  
pp. 928-931
Author(s):  
G. V. Burlakov
Keyword(s):  
Spinal Cord ◽  
Local Tetanus ◽  
Reflex Responses ◽  
Motor Nuclei

scholarly journals Cutaneous inputs from perineal region facilitates and modulates spinal locomotor activity and reduces cutaneous reflexes from the foot in spinal cats

2020 ◽  
Author(s):  
Angèle N Merlet ◽  
Jonathan Harnie ◽  
Madalina Macovei ◽  
Adam Doelman ◽  
Nathaly Gaudreault ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Nerve Stimulation ◽  
Rhythmic Activity ◽  
Short Latency ◽  
Cutaneous Reflexes ◽  
Excitatory Effect ◽  
Reflex Responses ◽  
Cutaneous Reflex ◽  
Weight Support ◽  
Perineal Region

AbstractIt is well known that mechanically stimulating the perineal region potently facilitates hindlimb locomotion and weight support in mammals with a spinal transection (spinal mammals). However, how perineal stimulation mediates this excitatory effect is poorly understood. We evaluated the effect of mechanically stimulating (vibration or pinch) the perineal region on ipsilateral (9-14 ms onset) and contralateral (14-18 ms onset) short-latency cutaneous reflex responses evoked by electrically stimulating the superficial peroneal or distal tibial nerve in seven adult spinal cats where hindlimb movement was restrained. Cutaneous reflexes were evoked before, during, and after mechanical stimulation of the perineal region. We found that vibration or pinch of the perineal region effectively triggered rhythmic activity, unilateral and bilateral to nerve stimulation. When electrically stimulating nerves, adding perineal stimulation modulated rhythmic activity by decreasing cycle and burst durations and by increasing the amplitude of flexors and extensors. Perineal stimulation also disrupted the timing of the ipsilateral rhythm, which had been entrained by nerve stimulation. Mechanically stimulating the perineal region decreased ipsilateral and contralateral short-latency reflex responses evoked by cutaneous inputs, a phenomenon we observed in muscles crossing different joints and located in different limbs. The results suggest that the excitatory effect of perineal stimulation on locomotion and weight support is not mediated by increasing cutaneous reflex gain and instead points to an excitation of central pattern-generating circuitry. Our results are consistent with a state-dependent modulation of reflexes by spinal interneuronal circuits.Significance StatementMechanically stimulating the skin of the perineal region strongly facilitates hindlimb locomotion in mammals following a complete spinal cord injury (SCI). Despite its remarkable effectiveness in promoting hindlimb locomotion in spinal cord-injured mammals, we do not know how this is mediated. The present study provides data on how inputs from the perineal region interact with neuronal circuits that generate locomotor-like activity and reflexes from the foot. A better understanding of how inputs from the perineal region interact with neuronal circuits of the spinal cord could lead to non-invasive approaches to restore walking in people with SCI.

Organization of the motor nuclei in the cervical spinal cord of salamanders

1988 ◽  
Vol 278 (2) ◽  
pp. 195-208 ◽  
Author(s):  
David B. Wake ◽  
Kiisa C. Nishikawa ◽  
Ursula Dicke ◽  
Gerhard Roth
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Motor Nuclei

Noradrenergic synapses and effects of noradrenaline on interneurons in the ventral horn of the cat spinal cord

1977 ◽  
Vol 55 (3) ◽  
pp. 399-412 ◽  
Author(s):  
Larry M. Jordan ◽  
David A. McCrea ◽  
John D. Steeves ◽  
John E. Menzies
Keyword(s):  
Spinal Cord ◽  
Close Contact ◽  
Cell Types ◽  
Muscle Afferents ◽  
Ventral Horn ◽  
Lumbar Spinal Cord ◽  
High Threshold ◽  
Depressant Action ◽  
Motor Nuclei ◽  
Lumbar Spinal

Histochemical and electrophysiological procedures were carried out to determine the cell types in the ventral horn which are in close contact with noradrenergic terminals and to identify the types of neurons in the ventral horn which are influenced by noradrenaline (NA). Fluorescence histochemical studies revealed that noradrenaline-containing fibers rarely form intimate contacts with alpha motoneurons, whereas many small interneurons which are closely invested with fluorescent fibers can be found near the motoneurons. The effects of microiontophoretically applied NA on interneurons were examined in the lateral motor areas of the lumbar spinal cord ventral horn. NA had a substantial depressant action on 43% of cells in chloralose-anesthetized and decerebrate cats; it excited 6% of the cells, and was without effect on the rest. The cells which were depressed by NA could be excited by electrical stimulation of high threshold muscle afferents or skin afferents, and they could be influenced from a variety of exteroceptive and proprioceptive inputs. Owing to considerable convergence on the affected interneurons, no distinct population of NA-sensitive interneurons could be identified. Many of the interneurons strongly depressed by NA were found near the motor nuclei. The hypothesis is presented that inhibitory actions of NA on interneurons in the motor nuclei might explain its hyperpolarizing action on motoneurons.

scholarly journals Spinal nociceptin mediates electroacupuncture-related modulation of visceral sympathoexcitatory reflex responses in rats

2009 ◽  
Vol 297 (2) ◽  
pp. H859-H865 ◽  
Author(s):  
Wei Zhou ◽  
Aman Mahajan ◽  
John C. Longhurst
Keyword(s):  
Spinal Cord ◽  
Receptor Antagonist ◽  
Intrathecal Injection ◽  
Inhibitory Effect ◽  
Ventrolateral Medulla ◽  
Gastric Distension ◽  
Reflex Modulation ◽  
Reflex Responses ◽  
Pressor Responses ◽  
Pressor Reflex

The role of nociceptin and its spinal cord neural pathways in electroacupuncture (EA)-related inhibition of visceral excitatory reflexes is not clear. Nociceptin/orphanin FQ (N/OFQ) is an endogenous ligand for a G protein-coupled receptor, called the N/OFQ peptide (NOP) receptor, which has been found to be distributed in the spinal cord. The present study investigated the importance of this system in visceral-cardiovascular reflex modulation during EA. Cardiovascular pressor reflex responses were induced by gastric distension in Sprague-Dawley rats anesthetized by ketamine and xylazine. An intrathecal injection of nociceptin (10 nM) at T1–2 attenuated the pressor responses by 35%, similar to the influence of EA at P 5–6 (42% decrease). An intrathecal injection of the NOP antagonist, [ N-Phe1]nociceptin1-13 NH2, partially reversed the EA response. Pretreatment with the opioid receptor antagonist naloxone did not alter the EA-like inhibitory effect of nociceptin on the pressor reflex, whereas a combination of nociceptin receptor antagonist with naloxone completely abolished the EA response. An intrathecal injection of nociceptin attenuated the pressor responses to the electrical stimulation of the rostral ventrolateral medulla by 46%, suggesting that nociceptin can regulate sympathetic outflow. Furthermore, a bilateral microinjection of NOP antagonist into either the dorsal horn or the intermediolateral column at T1 partially reversed the EA inhibitory effect. These results suggest that nociceptin in the spinal cord mediates part of the EA-related modulation of visceral reflex responses.

Motor nuclei of peroneal muscles in the cat spinal cord

1988 ◽  
Vol 277 (3) ◽  
pp. 430-440 ◽  
Author(s):  
G. Horcholle-Bossavit ◽  
L. Jami ◽  
D. Thiesson ◽  
D. Zytnicki
Keyword(s):  
Spinal Cord ◽  
Motor Nuclei
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