THE GALVANICALLY-INDUCED VESTIBULOOCULAR REFLEX IN THE CAT

Rotatory vestibular input is processed by receptor organs and relayed along the vestibular nerves to a central processor, whence the vestibu lo-ocular reflex (VOR) is generated. Electrical stimuli applied to the labyrinth can bypass receptors and stimulate the nerve directly, ther eby generating horizontal eye movements (EVOR). It was our purpose to mathematically relate the EVOR to the VOR in an effort to generate a p arameter by which the experimental effects of ototoxins on the inner e ar can be evaluated. A feline preparation was created in which the VOR and EVOR were measured in response to various sinusoidal stimuli. A d etailed comparison between VOR and EVOR with respect to gain and phase was performed. From analysis of the data, the differential sensitivit y to rotatory amplitude with respect to electrical amplitude was propo sed as this parameter.