Generation of auditory brain stem responses (ABRs). III. Effects of lesions of the superior olive, lateral lemniscus and inferior colliculus on the ABR in guinea pig.

Auditory brain stem potentials were recorded between the skull (vertex) and a non-cephalic reference in guinea pig before and after making discrete lesions of the auditory pathway in the pons and midbrain. Lesions of the superior olivary complex were accompanied by attenuation of P3 and N3 to contralateral input. Lesions of the lateral lemniscus were accompanied by attenuation of N3 to contralateral input. Lesions of the lateral portion of the pons adjacent to the lateral superior olivary nucleus were accompanied by attenuation of P4 to ipsilateral input. Lesions of the inferior colliculus were without effect on the ABR. These data are interpreted as supporting the hypothesis that each component of the ABR arises from a focal region of the brain stem auditory pathway.