[Patterns of cell proliferation in the avian vestibular epithelium on physiological and pathological condition]

To investigate the characteristic of cell proliferation in chick vestibular epithelium upon physiological and pathological condition.

The chicks received daily intramuscular injections of gentamicin sulfate (60 mg/kg) for 10 days. At 1,7 days after the last GM injection, the chicks received an intraperitoneal injection of 5-bromodeoxyuridine (BrdU; 100 mg/kg), and 6 hours later, they were sacrificed and the temporal bones epithelium. In physiological group, animals only received an intraperitoneal injection of BrdU.

A small number of labeled hair cells and supporting cells were found on physiological basis in all ampullary and otolithic organs, however the treatment group had a much larger number of labeled cells than the untreated animals. The labeled hair cells can immigrate and locate finally at the surface layer of the vestibular epithelium. Additionally, in many tissue sections,more than half of the labeled hair cells are aligned with labeled supporting cells.

The level of cell proliferation in the chick's vestibular system can be up-treated in response to a lesion. The supporting cells may be progenitors of the regenerated vestibular hair cells.