Figure 4.

Analysis of hair cell integrity after exposure to high cisplatin concentrations. Explants were treated as follows: 24 h in 100 μM cisplatin (A,B), 24 h in 500 μM cisplatin (C,D) or 24 h in 500 μM, followed by 24 h in normal growth medium (E,F). Organs were then co-stained for F-actin (phalloidin, green), MYO7A (gray), cleaved casp-3 (red) and Hoechst (blue), colors are used in merged images only. In the merged images of (C,D), the MYO7A (gray) signal, for which a high image gain was used for better visibility, was omitted. (A,C,E) are optical sections at the level of hair bundles (top section) and outer hair cell nuclei (bottom section). (B,D,F) are side views (generated by Reslice function in ImageJ), with the yellow dotted lines indicating the level of optical sections used in (A,C,E). The protected hair cells at high cisplatin concentrations (500 μM) display normal nuclear morphology. Continuing the culture for 24 h in normal growth medium leads to near complete recovery of MYO7A immunoreactivity in hair cells initially exposed to 500 μM cisplatin. Scale bar 20 μm.