Intermediate filaments in the inner ear of normal and experimentally damaged guinea pigs

The hypothesis that proteins known to occur in glial cells in the central nervous system may be present in inner-ear supporting cells was investigated. Immunocytochemical techniques were used to look for the existence of two classes of intermediate filaments, vimentin and glial fibrillary acidic protein (GFAP), in cellular elements of the inner-ear epithelium in normal and experimentally damaged guinea-pig cochleas. Vimentin is present in two types of supporting cells in the normal organ of Corti: Deiters' cells and inner pillar cells. Differences in intensity and distribution of vimentin immunostaining are observed across the three rows of Deiters' cells. GFAP immunoreactivity was not detected in any supporting-cell type in the organ. Cochlear hair cells were not labeled for either GFAP or vimentin. Following hair-cell destruction by exposure to noise or the administration of aminoglycosides, GFAP and vimentin are not present in phalangeal scars replacing lost hair cells.