Changes in inner ear fluids.

To the Editor .—In the article "Sodium and Potassium Changes in Inner Ear Fluids" by Nakashima et al ( 92 :1-6, 1970) the authors report large shifts in endolymph sodium and potassium ion concentrations following intense acoustical stimulation of the guinea pig's inner ear (140 dB). These changes failed to return to normal after the stimulation was stopped. These results appear to me to be caused by a rupture of the Reissner's membrane and not by an increased permeability of the Reissner's membrane as the authors suggest. In these experiments, histological study of serial sections of the guinea pig's inner ear would provide the necessary information to interpret these results. Histological or electron microscopic study is frequently necessary before interpreting experiments on the inner ear.