Intercellular Fluid Pathways in the Organ of Corti of Cat and Man

The intercellular junctions in the organ of Corti of cat and man were examined with the electron microscope. In contrast to the zone of tight junctions, or zonulae occludentes, which were present at the surface of cells lining the scala media, there was no tight junctional specialization among the cells of the tympanic lamina, perilymphatic lining cells of the scala vestibuli, basal processes of the supporting cells of the organ of Corti or cells of the spiral limbus and spiral ligament. These findings suggest the possibility of fluid continuity between the scala vestibuli and scala tympani all along the cochlear duct. Morphological evidence for an intercellular diffusion barrier was present only at the endolymphatic surfaces of the cochlear duct and between the processes of the basal cells of the stria vascularis in cat and man.