ABSTRACT
The presence of ganglio-N-tetraosylceramide (asialo GM1)-positive cells in mouse cochlea was tested for using an immunohistochemical method with an anti-asialo GM1 antibody which reacts with natural killer cells and macrophages in mouse. Only a few asialo GM1-positive cells were present on the surface of the scala tympani of the basal turn near the collecting venules. Transmission electron microscopic study showed the internal structure of these cells to be that of macrophages. These findings suggest that asialo GM1-positive cells function as resident type macrophages against invasion by pathogens of the mouse cochlea.
Subject(s)
Cochlea/cytology , G(M1) Ganglioside/analysis , Animals , Antibodies , Basilar Membrane/cytology , Cochlea/blood supply , Cochlear Aqueduct/cytology , Coloring Agents , Female , Immunohistochemistry , Killer Cells, Natural/cytology , Macrophages/cytology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Microscopy, Electron , Scala Tympani/cytology , Venules/cytologyABSTRACT
The morphologic features of the human cochlear aqueduct were examined using both light and electron microscopy. The lumen of the cochlear aqueduct was observed to be filled with dense, irregular connective tissue corresponding to dura mater. At the entrance to the cerebrospinal fluid space, the dense connective tissue in the ductal lumen was covered with a thin layer of a few flattened cells, which was contiguous with the arachnoid membrane of the brain. A simple low cuboidal epithelium also separated the perilymphatic space from the lumen of the duct. Our observations confirm the presence of a barrier membrane at the opening to the perilymphatic space, and suggest that no transport occurs in the human cochlear aqueduct.
