FINE-STRUCTURE OF THE HUMAN COCHLEAR AQUEDUCT - A LIGHT AND TRANSMISSION ELECTRON-MICROSCOPIC STUDY OF DECALCIFIED TEMPORAL BONES

The morphologic features of the human cochlear aqueduct were examined using both light and electron microscopy. The lumen of the cochlear aq ueduct was observed to be filled with dense, irregular connective tiss ue corresponding to dura mater. At the entrance to the cerebrospinal f luid space, the dense connective tissue in the ductal lumen was covere d with a thin layer of a few flattened cells, which was contiguous wit h the arachnoid membrane of the brain. A simple low cuboidal epitheliu m also separated the perilymphatic space from the lumen of the duct. O ur observations confirm the presence of a barrier membrane at the open ing to the perilymphatic space, and suggest that no transport occurs i n the human cochlear aqueduct.