EVIDENCE FOR SUPPORTING CELL-PROLIFERATION AND HAIR CELL-DIFFERENTIATION IN THE BASILAR PAPILLA OF ADULT BELGIAN WATERSLAGER CANARIES (SERINUS-CANARIUS)

Citation
O. Gleich et al., EVIDENCE FOR SUPPORTING CELL-PROLIFERATION AND HAIR CELL-DIFFERENTIATION IN THE BASILAR PAPILLA OF ADULT BELGIAN WATERSLAGER CANARIES (SERINUS-CANARIUS), Journal of comparative neurology, 377(1), 1997, pp. 5-14
Citations number
45
Categorie Soggetti
Neurosciences
ISSN journal
00219967
Volume
377
Issue
1
Year of publication
1997
Pages
5 - 14
Database
ISI
SICI code
0021-9967(1997)377:1<5:EFSCAH>2.0.ZU;2-Q
Abstract
We used the bromodeoxyuridine technique to study the proliferative act ivity in the basilar papilla of normal and Belgian Waterslager canarie s with and without preceding sound trauma. Without sound trauma, there were, on average, six supporting cell divisions per day in the basila r papilla of Waterslager canaries. This rate of supporting cell prolif eration corresponds well with estimates of the rate of hair cell diffe rentiation derived from counts of immature-appearing hair cells obtain ed by using scanning electron microscopy of the Waterslager basilar pa pilla. Thus, supporting cell division appeared correlated with hair ce ll differentiation in Waterslager canaries. Bromodeoxyuridine labeling of cells in undamaged non-Waterslager canaries also indicated a very low rate of supporting cell division. In contrast with Waterslager can aries, this low rate of proliferation was not associated with a measur able rate of hair cell differentiation. In both normal and Waterslager canaries, exposure to traumatizing sound induced a dramatic increase in the rate of cell proliferation. These data show that a very low rat e of supporting cell proliferation is normally present in birds, but i t is not associated with a corresponding rate of differentiation of ha ir cells. Only an increase above this low ambient rate of supporting c ell proliferation, such as that following loss of hair cells, induces the differentiation of new hair cells in birds. The reason why Watersl ager canaries do not completely compensate for their inherited hair ce ll deficit of 30% is not clear, when they can clearly respond to addit ional cochlear trauma from noise exposure with an increase in prolifer ation rate. (C) 1997 Wiley-Liss, Inc.