Nuclear fragmentation of astrocytes after treatment with ethanol. In this experiment, astrocytes were incubated with ethanol (1 %, v/v) for 21 hours, fixed in methanol/acetic acid (3:1) and stained with bisbenzimide (Hoechst 33258, 1 μg/ml). The characteristic condensation and fragmentation of nuclei indicates apoptosis. Enlargement: left picture, 400 fold; right picture, 1,000 fold. The experiment was repeated three times with similar results.