Repeated low-dose intraperitoneal lipopolysaccharide injections do not induce loss of striatal tyrosine hydroxylase-immunopositive terminals or dopamine depletion in DJ-1−/− or wild-type mice. (A) Densitometric analysis of striatal tyrosine hydroxylase (TH) fiber density indicates no significant differences between genotypes or treatment groups as indicated by Kruskal-Wallis with Tukey’s post hoc test. Bars represent mean ± SEM; analysis includes n = 3 to 7 per group in final cohorts due to attrition. The asterisk represents difference between bracketed groups and DJ-1−/− LPS. (B) Representative striatal sections stained for TH from mice in the 3 month treatment groups; scale bar = 400μm. (C) Striatal levels of dopamine (DA) were measured by HPLC electrochemical detection for mice in the 3-month treatment group and striatal DA turnover was calculated as the ratio of DA metabolites (DOPAC, HVA and 3-MT) to DA. Asterisks indicate significant differences compared with wild-type animals by two-way analysis of variance followed by Bonferroni’s HSD post hoc test at *P < 0.05 and ***P < 0.001 (Genotype effect for DA: F(1,30) = 26.01, P < 0.001; DA turnover: F(1,29) = 23.49, P < 0.001). IOD, integrated optical density; LPS, lipopolysaccharide; mo, months; DA, dopamine.