Figure 6. FK506 (tacrolimus) protects 661w cell cultures from staurosporine-induced cell death. A: FK506 (1 μM) significantly protected 661w neuronal cell cultures from staurosporine-induced apoptosis. Cell survival was monitored with the calcein-AM/propidium iodide cell-survival assay (scale bar=100 µm). The 661w neuronal cell cultures were treated with 1 μM FK506, with 1 μM staurosporine, with both 1 μM FK506 and 1 μM staurosporine, or with vehicle for 24 h. B: The 1 μM FK506 treatments significantly protected 661w neuronal cell cultures from 1 μM staurosporine-induced apoptosis (p<0.001, n=3). Error bars represent SEM.