Fig. 7.
Death of sympathetic neurons treated with SN50 is time- and dose-dependent. A, Neuronal cultures were either deprived of NGF (black line, filled triangles) or treated with 100 μg/ml SN50 in the presence of NGF (dashed line, open squares). Survival was assayed by MTT reduction at 12, 30, 48, and 72 hr after a single application of SN50. Data represents the mean ± SEM from three independent experiments. B, Neuronal cultures were treated with a single application of 50, 75, or 100 μg/ml SN50 (open bars) or SN50M (filled bars), both in the presence of NGF. Viability was assayed after 48 hr of treatment by Nissl staining as described in Materials and Methods. The results represent the mean ± SEM of at least three independent experiments. For both A andB, results are expressed as a percentage of the survival of control neurons maintained in the continuous presence of NGF.