Auditory brainstem responses, electrocochleograms, and cochlear microphonics in the myelin deficient mutant hamster ‘ bt’

Abstract

Electrophysiological studies of the auditory pathway were performed on the mutant hamster ‘ bt’ which is known to have myelin deficiencies in the central nervous system. Auditory brainstem responses (ABRs), electrocochleograms (EcochGs), and cochlear microphonics (CMs) were recorded. ABRs in ‘ bt’ demonstrated markedly transformed waveforms with significantly prolonged latencies. EcochG in ‘ bt’ showed significantly prolonged N1 latencies of the compound action potentials (CAPs) while ‘ bt’ showed normal CMs. The myelin deficient mutant hamster ‘ bt’ may have myelin deficiencies not only in the brainstem auditory pathway but also in the cochlear nerve.