Permeability of the Inner Ear Membranes

Soluted substances can penetrate through epithelial layers either by free diffusion through the intercellular spaces or by transcellular transport. By injection of th. as a tracer into peri- and endolymph we found a typical transcellular transport of the tracer through Reissner's membrane in micropinocytosis vesicles. Contrary to this observation, the tracer entered the "cortilymph spaces" from sc. tympani by free diffusion through open intercellular spaces. The sensory cells take up the tracer at their infranuclear area. We therefore conclude that "cortilymph" is perilymph and the hair cells of Corti's organ are mainly supplied from the perilymph side.