Figure 3

MPTP-induced microglial activation is inhibited by the selective COX-2 inhibitor valdecoxib. A: At 14 days post-MPTP injection, there was a high level of microglial activation in the SNpc. Unlike the vehicle group, mice treated with valdecoxib have diminished microglial activation. Pictures on the right are magnified photographs of the pictures on the left side. In contrast to inactivated striped microglia in MPTP+valdecoxib and control saline sections, activated microglia in MPTP+vehicle sections have a rounder body, fatter processes and denser stain. B: MPTP treatment leads to a significant increase in the number of activated microglia in mice receiving vehicle or the lowest dose of valdecoxib (10 mg/kg daily) but not the higher dose of valdecoxib (30 or 50 mg/kg daily). 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.