ASA 125th Meeting Ottawa 1993 May

4aPP14. Changes in distributions of fodrin and F-actin in the cochlea after noise exposure as revealed by confocal microscopy.

Vlasta Spongr

Giuseppe Attanasio

Donald Henderson

Hear. Res. Labs., State Univ. of New York at Buffalo, 215 Parker Hall, Buffalo, NY 14214

Changes in distributions of two cytoskeleton proteins, 240 kD alpha fodrin and filamentous actin, were studied in chinchillas exposed to 125 dB SPL impact noise and sacrificed immediately or 24 h after the exposure. To preserve the physiological integrity of the organ of Corti as much as possible, the surface preparations were studied using confocal fluorescence microscopy by serial, noninvasive optical sectioning. Immediately after noise exposure the damaged OHCs showed staining at the cuticular plates for both proteins, which varied in intensity. However, the lateral surfaces of the hair cells were not labeled. After 24 h, scars have replaced the missing cells and intense labeling of F-actin was seen in the Deiter's cells bodies and phalangeal processes. The results will be discussed in terms of role of fodrin and F-actin in the pathology induced by noise exposure. [Work supported by NIDCD 1R01DC01237-O1A1.]