Delineation of cochlear glycogen by electron microscopy.

Two techniques for the demonstration and identification of glycogen by electron microscopy were applied to the cochlear duct tissues of normal guinea pigs and chinchillas. A modified osmium tetroxide fixative (with potassium ferricyanide) has been described by De Bruijn to selectively stain the glycogen particle. Identification of the stained particle was effected by its selective removal from the tissue with amyloglucosidase, an enzyme specific in its degradation of the glycogen molecule. Glycogen particles were noted in several cell types within the cochlear duct, but concentrations were greater in outer hair cells of both species and in the stria vascularis of the chinchilla. The fact that amyloglucosidase completely eliminated these particles from the liver of both species as well as cochlear tissue, led to the conclusion that these particles are indeed glycogen.