The cell coat of the olfactory epithelium proper and vomeronasal neuroepithelium of the rat as revealed by means of the Ruthenium-red reaction.

The apical cell coat of the olfactory epithelium proper and the vomeronasal neuroepithelium of the rat was investigated electron-microscopically by means of the Ruthenium-red reaction. In the olfactory epithelium proper, the cilia of receptor cells and microvilli of supporting cells possess a cell coat measuring approximately 10 nm in thickness. In the vomeronasal neuroepithelium, the apical cell coat is thicker than in the olfactory epithelium proper. On microvilli of vomeronasal receptor cells the cell coat varies in thickness from 15 to 20 nm, and on microvilli of supporting cells it measures approximately 75 nm. The functional implications of these findings are discussed.