Hair cell death induced by CoCl₂ exposure.

<p>Cochlear explant cultures from P4 rats were treated with different concentrations of CoCl₂ for 24 h. Explants were stained with TRITC-labeled phalloidin and observed using confocal microscopy. A. Representative micrograph of control explants showing an orderly row of IHCs and three rows of OHCs with stereocilia bundles. B. Representative micrograph of explants exposed to 300 μM CoCl₂ showing loss of IHCs and OHCs. C. Representative micrograph of explants exposed to 400 μM CoCl₂ showing loss of a large number of hair cells with widened intercellular spaces. Bar, 20 μm. IHC, inner hair cell; OHC, outer hair cell.