Cytoplasmic Basophilia in Spiral Ganglion Cells of the Guinea-Pig Following Strong Acoustic Stimulation

Abstract

Forty-five anesthetised guinea-pigs were subjected to white noise at a level of 127 db for one hour, as a free field stimulus. At intervals of from 0 up to 31 days after the application of the stimulus, the animals underwent autopsy and were examined by cytophotometry for the degree of cytoplasmic baso-philia in the cells of the spiral ganglion, following staining by gallocyanin-chrome alum at pH 1.64, to indicate the relative changes in RNA content. The ganglion cells were also measured for possible changes in size. An initial fall in the cytoplasmic basophilia was found, but in the course of two weeks this gradually returned to normal values, as indicated by nine control animals. No significant change in cell size could be found which might be ascribed to the acoustic stress. It was further concluded that guinea-pigs could tolerate an acoustic stimulus of this magnitude, and that ganglion cell degeneration, previously observed following shock waves of the same intensity, must be secondary to destruction of the organ of Corti.