[Role of the nucleus vestibularis medialis in vestibulo-sympathetic response in rats].
Experiments were performed on rats anesthetized with alpha-chloralose and urethane. The sympathetic response evoked by stimulation of the vestibular nerve root at its entrance to brain-stem was recorded from the ipsi-splanchnic nerve. Electrical stimulation of the vestibular nerve elecited a distinct averaged response in the ipsilateral splanchnic nerve. The mean latency of response was 45.8 +/- 6.98 ms with a duration of 55.21 +/- 5.35 ms. With increasing the strength of stimulation, the amplitude of response was increased, but the latency was unchanged. By monitoring the lamellar field potentials in NVM and choosing the locus of phase-reversal of field potential as the stimulating site, an averaged response in ipsi-splanchnic nerve with a latency of 32 ms was obtained, while the recorded splanchnic nerve response had a latency of 43 ms, when the vestibular nerve was stimulated. After electrolytic lesion of the rostral part of ipsi-NVM, the vestibulo-sympathetic response was significantly reduced. When a second lesion was placed in the caudal NVM, the response disappeared. Lesion in Deiters' nucleus had no effect on the vestibulo-sympathetic response. The results suggest that NVM is a critical relay station in vestibulo-sympathetic response recorded in the splanchnic nerve.
Pan
P S
PS
Second Military Medical University, Shanghai.
Zhang
Y S
YS
Chen
Y Z
YZ
D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013153:Splanchnic Nerves / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D014725:Vestibular Nerve / Q000502:physiology; D014726:Vestibular Nuclei / Q000502:physiology*