Figure 3. Cell death revealed by caspase 3 activity. In the absence of taurine or the gap-junctional channel blocker octanol, an antibody to active caspase 3 shows that cell death induced by incubation with cytochome C (cyC) was widespread, extending to cells beyond the scrape (upper panels). In contrast, cell death in the presence of taurine (middle panels) or octanol (lower panels) was limited primarily to cells along the lines of the scrape. White lines indicate the position and approximate extent of the scrape. Scale bars represent 50 μm.