Accession Number : AD0431211

Title :   VESTIBULAR SUPPRESSION,

Corporate Author : MICHIGAN UNIV ANN ARBOR SCHOOL OF MEDICINE

Personal Author(s) : McCabe,Brian F.

Report Date : NOV 1963

Pagination or Media Count : 21

Abstract : Repeated stimulation of the vestibular endorgan of the inner ear produces a response decline which has been termed habituation and which we term vestibular suppression. Machinery was constructed to produce high rotary acceleration in a finely controlled manner to study this phenomenon in cats. Suppression was found to be long lasting and to reach about 60% of original response. It was most rapidly produced at just submaximal levels of stimulus. Postrotatory nystagmus duration was chosen as the response characteristic for reasons stated, after study of nystagmus parameters. Punishment slowed down the rate of acquisition of suppression in one cat. Intensity function studies, nerve block studies, and increment-decrement intensity function curves not only failed to show presence of functional endorgan damage due to high rates of deceleration but demonstrated the endorgan to be a good deal more rugged than is generally recognized. Transference of effects between the otolith organs and ampullae, using rotation and linear acceleration, was absent. The locus of suppression was shown to be most likely in the pontine reticular formation and not in the nucleus fastigius. The theory of efferent vestibular bundle causation was considered. All lesions were proven histologically. Linear acceleration studies demonstrated an otolithoocular reflex which can produce nystagmic eye movements. (Author)

Descriptors :   (*HEARING, INHIBITION), (*ACCELERATION, HEARING), EAR, PHYSIOLOGY, EYE, MOTION, STIMULATION(PHYSIOLOGY), CATS, HISTOLOGY, BIOPHYSICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE