DISTRIBUTION, STRUCTURE, AND FUNCTION OF DARK CELLS IN VESTIBULAR LABYRINTH

Dark cells are found consistently in the vestibular labyrinths of vertebrates such as the guinea pig, bat, cat, opossum, monkey and man. In the guinea pig, a fairly close relationship was found to exist between zones of dark cells and subepithelial melanocytes. The dark cells form a distinct pattern in the ampullae, utricle and common crus. In all ampullae, the dark cells are localized at the base of the cristae on the canal side, but are found nearly surrounding the opening on the utricular side. In the utricle, dark cells almost cover the entire posterior wall and the periphery of the anterior wall. In the common crus, dark cells are located on the lateral endolymphatic wall continuing from the inferior part of the utricle to the vicinity of the junction of the superior and posterior semicircular canals. They are not found in the saccule, saccular duct, ductus reuniens and main parts of the canals. Ultrastructure of the dark cell suggests that these cells play a significant role in the active transport of electrolyes in the vestibular labyrinth. © 1969, SAGE Publications. All rights reserved.