Pathological changes in the organ of Corti in presbyacusis as revealed by microslicing and staining.

A new technique of examining the organ of Corti in the perfused human cochlea is described. The fixed cochlea is microsliced and surface preparations are prepared and then stained for light microscopy. A method of assessing the distance/length ratio of samples is also described. Counts of inner and outer hair cells in such stained surface preparations were performed on elderly subjects and compared with those of infants. A marked loss of outer and a mild loss of inner hair cells was present in the elderly subjects. Complete atrophy of variable lengths of the terminal basal coil cells was also found in all elderly cochleas. Giant stereociliary degeneration takes place in hair cells (except basal coil outer hair cells) before they disappear.