Accession Number : AD0624663

Title :   BILATERAL REPRESENTATION OF THE HORIZONTAL SEMICIRCULAR CANALS IN THE INFERIOR VESTIBULAR NUCLEUS OF CATS.

Descriptive Note : Master's thesis,

Corporate Author : TEXAS A AND M UNIV COLLEGE STATION

Personal Author(s) : La Croix,John Thomas

Report Date : AUG 1965

Pagination or Media Count : 42

Abstract : The existence of bilateral representation was demonstrated in single units in the inferior vestibular nucleus of decerebrate, decerebellate cats by recording the spike potentials with tungsten microelectrodes. Recording electrodes one to two microns in diameter were stereotaxically placed in the inferior vestibular nucleus. Recordings were made from locations where the frequency of action potentials was affected by the direction of acceleratory stimulation of the horizontal semicircular canals. The ipsilateral and contralateral eighth cranial nerves were stimulated individually by one second galvanic pulses. The individual spike potentials were amplified and recorded on moving film from the screen of a cathode ray oscilloscope. Response to electrical stimulation was demonstrated by changes in the impulse rate at the recording site. Responses were elicited by stimulation of the nerves of both sides in almost all observations. The effect of stimulation of the contralateral side was, however, usually lesser in degree than the effect in the ipsilateral side. Other effects of stimulation were also noted. The possibility that responses were due to current spread from the site of stimulation was eliminated by demonstrating the lack of response in the sectioned nerve. Electrode placements were determined histologically. (Author)

Descriptors :   (*SEMICIRCULAR CANALS, ELECTROPHYSIOLOGY), (*AUDITORY NERVE, STIMULATION(PHYSIOLOGY)), VESTIBULAR APPARATUS, BRAIN, NERVE CELLS, NERVE FIBERS, NERVE IMPULSES, ANATOMY, PHYSIOLOGY, HISTOLOGY, CATS

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE