Abstract
The purpose of the present study was to determine whether spinal interneurons play a role in the regulation of sympathetic activity in spinally intact rats. In acutely spinally transected rats, we have described a population of spinal interneurons that, by virtue of correlations between their ongoing firing rates and the magnitude of ongoing renal sympathetic nerve activity (RSNA), are candidates for generators of sympathetic activity. Further evidence for a sympathetic role for these neurons comes from our observation that cervical spinal stimulation that reduces RSNA also reduces their discharge rates. In chloralose-anesthetized, spinally intact and spinally transected rats, we recorded ongoing RSNA and the ongoing activities of T10 dorsal horn and intermediate zone interneurons, and we determined the incidence of sympathetically related neurons in these rats by cross-correlating their activities with RSNA. The incidence of correlated neurons was much smaller in spinally intact than in spinally transected rats. We stimulated the dorsolateral, C2-3 spinal cord before and after acute C1 spinal transection. Dorsolateral cervical stimulation in spinally transected rats reduced both RSNA and the activities of most T10 interneurons, but stimulation in spinally intact rats increased RSNA while still reducing the activities of most T10 interneurons. Both the low incidence of sympathetically correlated spinal neurons in intact rats and the dissociation between the effects of cervical stimulation on RSNA and the discharge rates of spinal interneurons argue against these neurons playing a major role in regulating sympathetic activity in intact rats.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 101-106 |
| Number of pages | 6 |
| Journal | Brain Research |
| Volume | 918 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Nov 9 2001 |
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Keywords
- Descending modulation
- Spinal reflexes
- Sympathetic nervous system
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Spinal interneurons play a minor role in generating ongoing renal sympathetic nerve activity in spinally intact rats. / Miller, Corin O.; Johns, Devin G.; Schramm, Lawrence.
In: Brain Research, Vol. 918, No. 1-2, 09.11.2001, p. 101-106.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spinal interneurons play a minor role in generating ongoing renal sympathetic nerve activity in spinally intact rats
AU - Miller, Corin O.
AU - Johns, Devin G.
AU - Schramm, Lawrence
PY - 2001/11/9
Y1 - 2001/11/9
N2 - The purpose of the present study was to determine whether spinal interneurons play a role in the regulation of sympathetic activity in spinally intact rats. In acutely spinally transected rats, we have described a population of spinal interneurons that, by virtue of correlations between their ongoing firing rates and the magnitude of ongoing renal sympathetic nerve activity (RSNA), are candidates for generators of sympathetic activity. Further evidence for a sympathetic role for these neurons comes from our observation that cervical spinal stimulation that reduces RSNA also reduces their discharge rates. In chloralose-anesthetized, spinally intact and spinally transected rats, we recorded ongoing RSNA and the ongoing activities of T10 dorsal horn and intermediate zone interneurons, and we determined the incidence of sympathetically related neurons in these rats by cross-correlating their activities with RSNA. The incidence of correlated neurons was much smaller in spinally intact than in spinally transected rats. We stimulated the dorsolateral, C2-3 spinal cord before and after acute C1 spinal transection. Dorsolateral cervical stimulation in spinally transected rats reduced both RSNA and the activities of most T10 interneurons, but stimulation in spinally intact rats increased RSNA while still reducing the activities of most T10 interneurons. Both the low incidence of sympathetically correlated spinal neurons in intact rats and the dissociation between the effects of cervical stimulation on RSNA and the discharge rates of spinal interneurons argue against these neurons playing a major role in regulating sympathetic activity in intact rats.
AB - The purpose of the present study was to determine whether spinal interneurons play a role in the regulation of sympathetic activity in spinally intact rats. In acutely spinally transected rats, we have described a population of spinal interneurons that, by virtue of correlations between their ongoing firing rates and the magnitude of ongoing renal sympathetic nerve activity (RSNA), are candidates for generators of sympathetic activity. Further evidence for a sympathetic role for these neurons comes from our observation that cervical spinal stimulation that reduces RSNA also reduces their discharge rates. In chloralose-anesthetized, spinally intact and spinally transected rats, we recorded ongoing RSNA and the ongoing activities of T10 dorsal horn and intermediate zone interneurons, and we determined the incidence of sympathetically related neurons in these rats by cross-correlating their activities with RSNA. The incidence of correlated neurons was much smaller in spinally intact than in spinally transected rats. We stimulated the dorsolateral, C2-3 spinal cord before and after acute C1 spinal transection. Dorsolateral cervical stimulation in spinally transected rats reduced both RSNA and the activities of most T10 interneurons, but stimulation in spinally intact rats increased RSNA while still reducing the activities of most T10 interneurons. Both the low incidence of sympathetically correlated spinal neurons in intact rats and the dissociation between the effects of cervical stimulation on RSNA and the discharge rates of spinal interneurons argue against these neurons playing a major role in regulating sympathetic activity in intact rats.
KW - Descending modulation
KW - Spinal reflexes
KW - Sympathetic nervous system
UR - http://www.scopus.com/inward/record.url?scp=0035834327&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035834327&partnerID=8YFLogxK
U2 - 10.1016/S0006-8993(01)02965-1
DO - 10.1016/S0006-8993(01)02965-1
M3 - Article
C2 - 11684047
AN - SCOPUS:0035834327
VL - 918
SP - 101
EP - 106
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1-2
ER -