EXPRESSION OF ALPHA-ACTININ IN THE STEREOCILIA OF HAIR-CELLS OF THE INNER-EAR - IMMUNOHISTOCHEMICAL LOCALIZATION

THE distribution of alpha-actinin was studied on surface preparations and cryosections from the organ of Corti of the adult rat by using pol yclonal and monoclonal antibodies to smooth muscle alpha-actinin. The polyclonal antibody used gave a positive immunoreactivity in the cutic ular plate of the hair cells, pillar cells and supporting cells. A spe cific labelling of the stereocilia of the outer hair cells (OHCs) and inner hair cells (IHCs) on surface preparations was highly visible. Th e monoclonal antibody used produces similar patterns of labelling in t he organ of Corti. The possible roles of this protein in hair cells ar e discussed.