Expression of c-Fos after noise-induced temporary threshold shift in the guinea pig cochlea.

c-Fos is known to be a component of a transcription factor, activator protein-1, which is induced by oxidative stress. Guinea pigs were exposed to 4 kHz band noise of 110 dB SPL for 1 or 5 h and the expression of c-Fos in the organ of Corti was determined using Western blotting analysis and immunocytochemistry. c-Fos was expressed only after the noise exposure. The c-Fos expression was mainly found in the Hensen's cells, Claudius' cells and Deiter's cells of the basal and second turns of the cochlea. Since the threshold shift was temporary, the expression of c-Fos is therefore considered to contribute to the survival or protective function of the organ of Corti.