Effects of bilateral sham or 6-OHDA lesion and chronic daily L-DOPA (12 mg/kg + benserazide, 15 mg/kg, sc; LD) on 5-HT/DA ratio at various time points post-L-DOPA administration. Animals were treated for 28-75 days and then killed at 20 min, 1 h, 4 h and 24 h after their respective treatments. Bars show the effects of group on tissue 5-HT/DA ratio in the (A) striatum, (B) hippocampus, (C) amygdala, and (D) prefrontal cortex. Average values from which the 5-HT/DA ratio was calculated are located in (E). Values are picogram monoamine or metabolite per milligram wet tissue weight or ratios of metabolite to monoamine (mean ± SE) with percent of Sham-VEH group in parentheses. Main effects of group were established by one-way ANOVA and subsequent Fisher LSD post hocs determined differences between groups [*p<0.05 vs. Sham-VEH, +p<0.05 vs. Lesion-VEH, #p<0.05 vs. Lesion-LD (20 min), @p<0.05 vs. Lesion-LD (1 h)].