Figure 2.

DT specifically eliminates hair cells in vitro in DTR mice. Cochlear explants were prepared from P2–P3 DTR and WT mice and subjected to either no treatment or DT administration (25 ng/ml) for 3 d in culture and then immediately fixed and subjected to immunolabeling. A, Untreated explants from DTR mice have intact inner hair cells (IHCs) and outer hair cells (OHCs) (red). B, Treatment of explants from DTR mice with DT induces extensive loss of OHCs and complete loss of IHCs. There is no apparent impact of DT on supporting cells (green). Scale bar, 50 μm. Insets in A and B show low-power views of one representative turn of corresponding explant cultures.