Frequency Selectivity of Acoustically Evoked Potentials from Peripheral and Central Vestibular Structures

Abstract

In the last few years an acoustico-neural transduction originating in the saccule was revealed in guinea pigs in which the cochlear receptor was completely and exclusively destroyed (Aran et al., 1979, Cazals et al., 1979). Preliminary investigations of this phenomenon showed electrophysiological responses characteristic of those from the eighth nerve (Cazals et al., 1979, 1980, 1982, 1983a). The responses were demonstrated to be of osaccular origin by means of experimental pathologies combining total or partial vestibular destruction with the complete loss of the cochlear receptor (Cazals et al., 1983b). The data together led to the supposition of activation of type I cells with an electrical synaptic transmission to eighth nerve fibers. The normal appearance of the vestibule (Cazals et al., 1985) in this model of experimental pathology suggests that a saccular acoustic reception may also exist in normal animals but be masked by normal cochlear functioning; such a view is consistent with phylogenetic considerations (Wever, 1974).