[The structure of the round window membrane studied by thin section.- freeze-fracture- and scanning electron...

In thin sections of the round window membrane of chinchilla there were found tight junctions between the cells of the outer and of the inner cell layer as well. Their structure was demonstrated in freeze-fracture replica, and in the scanning electron microscope both faces of the membrane appeared uninterrupted. The tight junctions between the mucosal cells constantly became visible and are considered impermeable; however, the junctions connecting the mesothelial cells, which face the perilymph, demonstrated high susceptibility against differences in preparation and were structurally different.