FLZ shows significant protective effect against the toxicity of MPTP in vivo. Eight-week-old male C57BL/6J mice received daily MPTP injections (15 mg/kg, s.c.) for 6 consecutive days. From the third day on, FLZ (75 mg/kg, p.o.) was administered 30 min before every MPTP injection for the last 4 days. DA neurotoxicity was measured by immunohistochemistry using an anti-TH antibody (A) and cell counting of DA neurons (B) in the SNpc of different groups of mice. To assess activation of microglia, SNpc brain sections were stained using Iba-1 antibody, a microglial maker (C). To obtain quantitative data, the midbrains of the mice were dissected out, and levels of Iba-1 in these midbrains were determined using western blot assays (D). To assess the protective effect of FLZ on MPTP-induced motor function deficiency, a rotor-rod assay was used and the time for each mouse to remain on the spinning rod was recorded (E). The data are expressed as mean ± S.E.M. for the results of 6–8 mice. # p < 0.05 and ## p < 0.01 compared with vehicle-treated control group; * p < 0.05 compared to MPTP treatment group. Scale bar, 50 μm.