The temperature dependence of electrical coupling in the organ of Corti

Electrical coupling in an in vitro preparation of the organ of Corti was evaluated during changes in temperature of the bathing media. The effect of cooling the organ from 35 +/- 2 degrees C to 17 +/- 3 degrees C is to reduce membrane potentials, increase input resistance and decrease coupling ratios. Decreases in coupling ratios ranging from 15 to 75% have been observed. The effects are reversible upon warming. Membrane potentials are very susceptible to depolarization caused by cooling. The reduction in coupling is not due to depolarization nor is it dependent upon extracellular Ca2+. It is conceivable, however, that intracellular stores of Ca2+ are released or that intracellular pH is altered.