Vestibular membrane

The vestibular membrane, vestibular wall or Reissner's membrane, is a membrane inside the cochlea of the inner ear. It separates the cochlear duct from the vestibular duct. Together with the basilar membrane it creates a compartment in the cochlea filled with endolymph, which is important for the function of the spiral organ of Corti. It primarily functions as a diffusion barrier, allowing nutrients to travel from the perilymph to the endolymph of the membranous labyrinth.

Histologically, the membrane is composed of two layers of flattened epithelium, separated by a basal lamina. Its structure suggests that its function is transport of fluid and electrolytes.

Reissner's membrane is named after German anatomist Ernst Reissner (1824-1878).