Study Of Electrophysiological And Neurotransmitter On Vestibular System Of Guinea Pigs

EXPERIMENT ONE: OTOTOXICITY OF GENTAMICIN ASSESSED BY VESTIBULAR EVOKED POTENTIALSIn order to assess ototoxity of gentamicin by the vestibular evoked potentials(VsEPs) and auditory brainstem response(ABR). 40 guinea pigs were divided into 4 groups. 10 of group A were injected gentamicin intramucle 60mg/kg/day. 10 of group B were injected Ns 0.9% 0.5ml/day as control. 10 of group C were given gentamicin intratympanic 5mg/kg/day. 10 of group D were given Ns 0.9% intratympanic injection 0.1 ml/day as control. ABR and VsEPs were measured prior to and following the administration. After treatment group A at 21 days, 40 days, the same as group C at 5 days, 10 days, ABR and VsEPs showed significant changes, corresponding to histopathological examination of the temporal bones. VsEPs is able to assess ototoxcity of gentamicin to inner ear.EXPERIMENT TWO: ENDOLYMPHATIC HYDROPS PRODUCTED BY ALDOSTERONEThe classical guinea pig model for Meniere's Disease with operation was single ear, aldosterone may develope endolymphatic hydrops in both ears. 26 animals were divided into 3 groups. 10 of group A received left ears operation, right ears non-operated as contral. 10 of group B introperitonal injection aldosterone 100ug/100mg/day, 6 of group C received introperitonal injection Ns 0.9% as control. 4 out of group A and B were killed during 1 month, 2 months alternative. In group A severe endolymphatic hydrops developed in the left ears during 1 and 2 months. In group B mild and moderate endolymphatic hydrops developed in the both sides ears during 1 month, severe endolymphatic hydrops developed 2 months. After injection, K 5.5mmol/L, Na 142mmol/L, Cl 112mmol/L and Ca 2.15mmol/L.EXPERIMENT THREE:VESTIBULAR PHYSIOLOGICAL RESEARCHPart One: Spontanous Activity Recorded in Vestibular Nerve and NucliIn order to study the variation of vestibular spontanous activity between normal and pathological statement, Glass microelectrode was used in extracellular recording. 18 animals were divided into 3 groups. 6 of group A as normal, two kinds of spontanous activity, such as regular and irregular could be recorded. 6 of group B left ears gentamicin intratympanic injection ,the dose was 5mg/kg/day successive 5 days. 6 of group C received introperitonal...