Fig. 1.

Effects of increases in 5HT on METH-induced depletion of striatal DA. Mice (N = 5–8/group) were treated with saline (control), 5HTP (50 mg/kg) + carbidopa (25 mg/kg), METH alone (4 injections of 5 mg/kg at 2 hr intervals) or with 5HTP + carbidopa 60 min before the first and third injections of METH and sacrificed 48 hr after the last injection. Striatal DA levels were determined by HPLC with electrochemical detection. Results are presented as mean ± SEM relative to controls. Differences between treatment groups were tested for significance by one-way ANOVA followed by Tukey’s multiple comparison test using Graphpad Prism 5. *** indicates significantly different from control (p < 0.001).