Fig. 2.
Time course. Mean (± SEM) percent of saline control (bFGF-immunoreactive cells per square millimeter) in the VTA and SNc in groups (n = 5 per group) of amphetamine-treated animals (3.0 mg/kg, i.p., on three occasions, once every other day) killed 24 hr, 72 hr, 1 week, and 1 month after the last injection. One hundred percent (100) represents the mean (solid line) and SEM (dashed lines) counts from saline-treated animals that were killed at each of the time intervals after the last injection (n = 15). ANOVAs performed on the actual counts showed a significant effect of drug treatment (VTA, F(4,30) = 11.61; p = 0.0001; SNc,F(4,30) = 16.85; p < 0.0001). Asterisks indicate significant differences from the saline group, p < 0.01; daggersindicate significant differences from the peak, p< 0.05.