[Acute morphological changes in guinea-pig cochlea following electrical stimulation].

The acute morphological changes of intracochlear electrical stimulation were studied in 42 guinea-pigs, which were divided into six groups. The electrode was implanted into the cochlea 1.5mm deep, and the cochlea was stimulated with intensities of 216 microA, 432 microA, 648 microA, 864 microA and 1080 microA for six hours. Morphological changes observed in the stimulated ears ranged from hair cell, nerve cell and supporting cell degeneration to complete destruction of the basilar membrane and organ of Corti overlying the electrode. These changes occurred at current intensities ranging from 432 to 1080 microA and were conspicuously absent in the implanted but unstimulated control ears and in the ears with 216 microA stimulation. Our observations also demonstrate that 432 microA stimulation can change the structure of the cochlea.