Source of the P₁ Component of the Cochlea Round Window Recording

Abstract

The cochlear round window potentials of cats and guinea pigs have been studied in their response to a short click stimulus coupled with specifically placed neural lesions. With the destruction of a specific area of the cochlear nucleus, by means of electrical coagulation, a loss of the positive portion of the potentials (P₁) occurred. This potential did not recover during 4 hours of observation in contrast to the extensive recovery observed within 2 hours after lesions were made at the internal auditory meatus (including the vestibular nerve and OCB fibers). The lack of recovery in the animals in which lesions were placed in the cochlear nucleus may be explained on the basis that the responsible neurons in this area were destroyed. Since the P₁ potential has a short latency with respect to the termination of microphonic activity and the changes are seen only with lesions placed peripherally to or at the specific cochlear nucleus area; it is proposed that the P₁ potential possibly represents an activity of a peripheral coding or inhibitory mechanism.