AJP - Regulatory, Integrative and Comparative Physiology, Vol 268, Issue 6 1381-R1385, Copyright © 1995 by American Physiological Society
Descending pathways necessary for vestibular influences on sympathetic and inspiratory outflow
B. J. Yates, M. S. Siniaia and A. D. Miller
Laboratory of Neurophysiology, Rockefeller University, New York, New York 10021, USA.
The objective of this study was to determine which brain stem regions that
have projections to sympathetic preganglionic neurons or phrenic
motoneurons ae necessary for vestibulosympathetic or vestibulorespiratory
responses in decerebrate cats. Bilateral kainic acid injections into the
rostral ventrolateral medulla abolished splanchnic nerve responses to
electrical stimulation of the vestibular nerve, suggesting that this region
is critical for the production of vestibulosympathetic responses. In
contrast, injections into the caudal medullary raphe nuclei had no apparent
effect on the responses. Neither the dorsal nor the ventral respiratory
group appears to be necessary for mediating vestibular influences on the
phrenic nerve, suggesting that nonrespiratory neurons (such as
vestibulospinal neurons) may be important for producing
vestibulorespiratory responses.
