Fig. 4.

Effects of genetic manipulation of PPARδ levels on MPTP neurotoxicity. PPARδ heterozygous mice have reduced PPARδ mRNA levels compared to their wild-type littermates (A). No difference is seen between wild-type mice and their heterozygous littermates (null mice were not viable) in their sensitivity to MPTP toxicity. Representative micrographs of TH- and Nissl-stained sections (B) (Scale bar = 200 μm). Both TH-positive neuron (C) and Nissl-positive neuron (D) numbers were reduced by MPTP in wild-type and heterozygous mice. No differences were detected in striatal TH-immunoreactivity (E and F) between wild-type and heterozygous mice. PPARδ protein levels in untreated mice were not significantly different between heterozygous mice and their wild-type littermates (G). Data are mean ± SEM, n = 6–7 mice per group for stereological counting and n = 3 mice per group for mRNA and protein analysis. ^∗∗p < 0.01; ^∗∗∗p < 0.001 (Student t-test (A) or ANOVA with Student–Newman–Keuls post hoc test) (WT – wild-type; Het – heterozygous; TH – tyrosine hydroxylase; SNpc – substantia nigra pars compacta).