Vestibular, cochlear and trigeminal projections to the cortex in the anterior suprasylvian sulcus of the cat

Abstract

Cats anesthetized with chloralose were used. Potentials evoked by electrical stimulation of the vestibular, cochlear, facial, trigeminal and chorda tympani nerves were recorded with micro-electrodes in the cortex in the anterior syprasylvian sulcus. Negative focal potentials with a latency of 3 msec were evoked by stimulation of the contralateral and ipsilateral vestibular nerves. These potentials were located in the lower and upper banks of the sulcus at a level just caudal to the projection of the Group I muscle afferents to the lower bank. The cochlear projections were located mainly in the lower bank partially overlapping the vestibular and the Group I fields. Trigeminal responses were recorded in both banks of the sulcus but were of largest amplitude and shortest latency rostrally in the upper bank. The potentials evoked by the chorda tympani had a similar distribution but were of low amplitude. The cortex in the anterior suprasylvian sulcus possibly plays a role in the orientation of the body and head towards auditory stimuli.