Vestibular nerve projection to the cerebral cortex of the rhesus monkey.

Abstract

1. Cortical potentials evoked by electrical stimulation of the vestibular nerve in the Rhesus monkey indicate that the primary receiving area for the vestibular nerve is located in the posterior part of the postcentral gyrus at the base of the intraparietal sulcus between the first and second somatosensory fields, probably in Brodmann's area 2. 2. An origin of the evoked cortical potential from other cranial nerves was excluded by extirpation of the cochlear, facial and intermedius nerves and by vestibular stimulation before and after section of the V, IX, X and XI nerve roots at the brainstem. Only sectioning the vestibular nerve abolished the response. 3. This field partially overlaps the SI cortical region responsive to electrical stimulation of the contralateral median nerve. There is interaction between vestibular and median nerve afferents within the overlap zone. 4. It is postulated that the primary cortical vestibular field contributes information for higher motor regulation and conscious spatial orientation.