DEMONSTRATION OF INTERMEDIATE FILAMENT PROTEINS IN THE GUINEA-PIG VESTIBULAR LABYRINTH BY A NEW, HIGH-RESOLUTION CRYOTECHNIQUE

In order to establish the more precise localization of IFPs in the ves tibular labyrinth we have developed an immunohistochemical method usin g semithin cryosections from guinea pig inner ear. The vestibular end organs were fixed by intralabyrinthine perfusion with formaldehyde and glutaraldehyde. Microdissection was performed, followed by decalcific ation in EDTA. After specimen embedding in gelatin, semithin cryosecti ons (1 mu m) were prepared. Prior to the immunohistochemical staining, a new antigen-unmasking treatment was performed. Monoclonal antibodie s for cytokeratins (Cks), vimentin, neurofilament protein (NF), and gl ial fibrillary acidic protein (GFAP) were used and visualized with an indirect ABC method. In the guinea pig vestibular labyrinth, Cks8, 18 and 19 were present. Vimentin and NF were stained positively, GFAP neg atively. These results are in accordance with our previous results in the human vestibular labyrinth except for Ck7. The high-resolution cry otechnique in combination with a new antigen-unmasking method may yiel d more, and more detailed information about the localization of IFPs i n the vestibular region.