Fig. 1. IGF-I protects otic vesicles from NGF-induced cell death. Apoptotic cell death was visualised by TUNEL in cultured otic vesicles. Otic vesicles were isolated from HH18 chicken embryos, made quiescent and cultured for 8 hours in serum-free medium (A, control), 4 nM NGF (B), 5 µM C₂-Cer (C) or 1 nM IGF-I (D) or the combination of IGF-I with NGF (E) or C₂-Cer (F). Compiled projections of the whole otic vesicle are shown. All otic vesicles have the same orientation: D (dorsal), A (anterior), cvg (cochleovestibular ganglion). The images shown are representative of at least three different experiments, using five otic vesicles by condition. Bar, 100 µm.