ACTIVITY OF THE SUPERIOR VESTIBULAR NUCLEI NEURONS AT STIMULATION OF HYPOTHALAMIC PARAVENTRICULAR AND SUPRAOPTIC NUCLEI IN CONDITIONS OF UNILATERAL LABYRINTHECTOMY COMBINED WITH VIBRATION EXPOSURE

We studied the frequency changes of single neuronal spike activity flow from superior vestibular nucleus (SVN), evoked on high frequency stimulation (HFS) of paraventricular (PV) and supraoptic (SO) nuclei of hypothalamus in Albino rats in conditions of unilateral labyrinthectomy (UL) combined with many days of vibration exposure (VE). Programmed mathematical on-linе analysis was used. In normal conditions, at bilateral stimulation of PV and SO nuclei the tetanic potentiation (TP) prevaled. After UL in control at uninjured side TP and posttetanic potentiation (PTP) were recorded; on injured side, on the whole, along with variability of initial background activity of SVN neurons, an exiguity of components and of the repeatability of poststimulus excitatory and inhibitory manifestations of SVN neurons’ activity were recorded. Combined action of UL and VE at intact side evoked tetanic depression on ipsilateral stimulation of PV and SO nuclei; on injured side the stimulation of the same nuclei evoked TP and PTP, which achieved normal levels. The results of histochemical investigation in analogous experimental conditions confirmed the electrophysiological data, which allowed us concluding about protective effect of VE.