FODRIN IMMUNOCYTOCHEMICAL LOCALIZATION IN THE STRIATED ORGANELLES OF THE RAT VESTIBULAR HAIR-CELLS

The immunocytochemical distribution of a spectrin-related protein, fodrin was studied at the electron microscopic level in the rat vestibular hair cells. As previously demonstrated [Scarfone et al., Neurosci. Lett. 93, 13-18, 1988], an intense immunoreactivity was found in the cuticular plates. We demonstrate furthermore, here, for the first time the association of fodrin immunoreactivity with the striated infracuticular structures called striated organelles (SO). Fodrin was found in striated structures clearly identified as SO in both Type I and Type II hair cells. SO were labelled regardless of their location, subcuticular or associated with the plasma membrane of the cells. We suggest that fodrin, as in the cuticular plate, could participate to the Ca2+ dependent cross-linking of the actin filaments of the striated organelles and could play a role in their interaction with the submembraneous cytoskeleton.