Increased spiral ganglion cell survival in electrically stimulated, deafened guinea pig cochleae

For implanted electronic prostheses to function successfully in the deaf, residual spiral ganglion neurons are presumed to be necessary. Several studies have tried to determine the effects cochlear electrode implantation and electrical stimulation have on the neurons of the spiral ganglion. Little work has been published, however, on the trophic effects of electrical stimulation on cell survival after cochlear damage by ototoxicity. This report presents the results of an investigation to determine the effects of early intracochlear electrical stimulation on spiral ganglion neuron survival after chemically induced deafness in young guinea pigs. A significantly larger number of spiral ganglion cells remained in stimulated ears 6 weeks after deafening than were seen in the unstimulated ears of the same animals. These results suggest that early implantation after acquired deafness may affect the success obtainable with electronic hearing prostheses.