TY - JOUR
T1 - Splanchnic and somatic afferent convergence on cervical spinal neurons of the rat
AU - Akeyson, E. W.
AU - Schramm, L. P.
PY - 1994
Y1 - 1994
N2 - The rostral cervical spinal cord is increasingly being considered the source of important propriospinal regulation. To better understand the substrate for this function, we investigated the effects of stimulation of the greater splanchnic nerve (GSN) and both thoracic and cervical somatic afferents on the activity of cervical spinal neurons. Extracellular single- neuron recordings were made in the C2-C5 spinal segments of chloralose- anesthetized, paralyzed, and artificially ventilated rats. Neurons were classified according to their responses to GSN stimulation. Neurons were inhibited by this stimulation as frequently as they were excited. We then studied the characteristics of cervical and thoracic convergent somatic input to each class of neurons. Although all cervical neurons that responded to GSN stimulation responded to electrical stimulation of the iliohypogastric nerve (IHN), only the few neurons that exhibited whole body receptive fields (RF) responded to natural thoracic somatic stimuli. Responses to electrical stimulation of the GSN and IHN were similar for most neurons; most exhibited nociceptive cutaneous RFs in cervical dermatomes. These data indicate that input from cervical somatic afferents and from both thoracic visceral and thoracic somatic afferents converge on individual splanchnic-receptive cervical neurons. Although these neurons exhibited the predicted cervical somatic RFs, responses from thoracic levels did not exhibit discrete RFs, requiring instead more synchronous or more spatially convergent input.
AB - The rostral cervical spinal cord is increasingly being considered the source of important propriospinal regulation. To better understand the substrate for this function, we investigated the effects of stimulation of the greater splanchnic nerve (GSN) and both thoracic and cervical somatic afferents on the activity of cervical spinal neurons. Extracellular single- neuron recordings were made in the C2-C5 spinal segments of chloralose- anesthetized, paralyzed, and artificially ventilated rats. Neurons were classified according to their responses to GSN stimulation. Neurons were inhibited by this stimulation as frequently as they were excited. We then studied the characteristics of cervical and thoracic convergent somatic input to each class of neurons. Although all cervical neurons that responded to GSN stimulation responded to electrical stimulation of the iliohypogastric nerve (IHN), only the few neurons that exhibited whole body receptive fields (RF) responded to natural thoracic somatic stimuli. Responses to electrical stimulation of the GSN and IHN were similar for most neurons; most exhibited nociceptive cutaneous RFs in cervical dermatomes. These data indicate that input from cervical somatic afferents and from both thoracic visceral and thoracic somatic afferents converge on individual splanchnic-receptive cervical neurons. Although these neurons exhibited the predicted cervical somatic RFs, responses from thoracic levels did not exhibit discrete RFs, requiring instead more synchronous or more spatially convergent input.
KW - autonomic nervous system
KW - cervical spinal cord
KW - propriospinal regulation
KW - splanchnic nerves
KW - visceral afferents
UR - http://www.scopus.com/inward/record.url?scp=0028119572&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028119572&partnerID=8YFLogxK
U2 - 10.1152/ajpregu.1994.266.1.r268
DO - 10.1152/ajpregu.1994.266.1.r268
M3 - Article
C2 - 8304549
AN - SCOPUS:0028119572
SN - 0002-9513
VL - 266
SP - R268-R276
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 1 35-1
ER -