Effect Of Central Vestibular Circuit To Contral Blood Pressure During Acute Hypotansion In Rats

Central role of the vestibular system on control of blood pressure and interrelationships between the vestibular nucleus and solitary nucleus during acute hypotension were unvestigated in bilateral labyrintehctomized (BLX) or sinoaortic denervated (SAD) rats. Changes of electrical activity in the medial vestibular nucleus(MVN), Solitary tract nucleus(STN) and rostral ventrolateral medullary nucleus(RVLM) were determined in rats in while acute hypotension was inducede by sodium nitroprusside(SNP).Evoked potential in MVN neuron caused by electrical stimulation of the peripheral vestibular system was composed of 3 waves with latencies of 0.48±0.10ms, 1.04±0.09ms and 1.98±0.19ms. Electrical stimulation to MVN or showed excitation in 61% of type I neurons and inhibition in 68% of type II neurons. In STN, acute hypotension produced excitation in 62.1% of neurons recorded in intact labyrinthine animals, inhibition in 72.3% of neurons recorded in BLX animals, and excitation in 60% of recorded neurons in SAD animals. In RVLM, acute hypotension produced excitation in 66.7% of neurons recorded in intact labyrinthine animals and inhibition in 64.9% of neurons recorded in BLX animals. These results suggest that afferent signals from the peripheral vestibular receptors are transmitted to STN through the vestibular neclei and...