Figure 4

Ablation of COX-2 reduces MPTP-induced microglial activation 7 days post-MPTP injection. A: Seven days after MPTP treatment, COX-2 +/+ mice had a local increase of microglial activation in the SNpc, which is shown with immunohistochemical stains for Mac-1, compared to saline-treated or MPTP-treated COX-2 +/- and -/- mice. The magnified right panels show activated microglia. In contrast to inactivated striped microglia in MPTP-treated COX-2-deficient and control saline sections, activated microglia in MPTP-treated COX-2 wild-type have a rounder body, fatter processes and denser stain. B: MPTP treatment leads to a significant increase in the number of activated microglia in the WT relative to the HT and KO mice. Activated microglia in the SNpc were bilaterally counted under a 40 × objective. Data are means ± SEM for six to eight mice per group, ***p < 0.001 compared to saline+vehicle group; ###p < 0.001 compared to MPTP+vehicle group, by ANOVA with subsequent Bonferroni for multiple comparisons. Scale bar, 100 μm.