Abstract
In order to elucidate the cell kinetics of the component cells of human cochlea, we have carried out the Feulgen-DNA cytofluorometry using serial section method (ref. Report I-III). The data obtained from 20 cases (0-87 years old) demonstrated that the hair cells have diploid G1 pattern in DNA distribution without any exception. The supporting cells, however, had polyploid cells in some cases; we found 29 tetraploid and one octaploid cell in Hensen's cells of 7 cases and two tetraplod cells in Deiters' cells of two cases. Interestingly, these Hensen's cells were found almost always in the neighborhood of the damaged or missing outer hair cells, while Deiters' cells in these area was swollen but remained to be diploid. Although both supporting cells seems to have the ability to repair the damaged organ of Corti by replacing the damaged or missing outer hair cells, the way to do so was quite diffrent; Hensen's cells seemed to involve nucleus (polyploidization) and Deiters' cells cytoplasma (swelling).
