AJP - Regulatory, Integrative and Comparative Physiology, Vol 240, Issue 5 348-R355, Copyright © 1981 by American Physiological Society
Sympathetic-related activity of brain stem neurons in baroreceptor-denervated cats
G. L. Gebber and S. M. Barman
A search was initiated in baroreceptor-denervated cats for brain stem
neurons with activity patterns related to inferior cardiac sympathetic
nerve discharge (SND). Neurons whose spontaneous discharges were followed
by increases or decreases in SND fell into two categories. S unit
discharges were related to SND but not electroencephalogram (EEG) activity.
The activity of SE units was related to SND and EEG activity. The anatomic
distribution of S and SE units was similar to that previously reported
[Barman and Gebber, Am J. Physiol. 240 (Regulatory Integrative Comp.
Physiol. 9): R335-R347, 1981] for units with activity patterns related to
SND in baroreceptor-innervated cats. Autocorrelograms of S unit discharges
and SND contained the same rhythm (2-6 cycles/s). This rhythm was different
from that contained in SE unit discharges and EEG activity in experiments
in which SND and cortical activity were not related. In other experiments,
sympathetic nerve and cortical rhythms were locked to each other. SE units
but no S neurons were located in these cats, and the rhythm contained
within the autocorrelograms of their discharges was the same as that
observed in SND and EEG activity. A model of brain stem networks, which
govern the discharges of sympathetic nerve, is presented on the basis of
these data.
