Effects of local application of ototoxic antibiotics on cochlear potentials in guinea pigs.

The effects of neomycin, kanamycin and dihydrostreptomycin on the cochlear microphonic, the action potential of the auditory nerve and the endocochlear potential were studied in guinea pigs in which these drugs were locally administered by perfusion. These drugs suppressed the cochlear responses markedly when applied to the endolymph but were less effective when applied to the perilymph. The mechanisms of action of antibiotics on the hair cells of the organ of Corti are discussed.