Figure 6.

Microglial activation and MMP9 production induced by S100B in situ is blocked by PARP-1 inhibition. A. Iba-1 immunostaining in striatum 3 days after injection with 0.5 μg S100B or saline vehicle and subsequent daily i.p. injection with veliparib or saline vehicle by. Scale bar = 200 μm. Insert boxes are magnified 4-fold to show cell morphology. B. Iba-1 immunostaining in brain sections from wild-type and PARP-1^−/− mice. The mice received 0.5 μg/ml intrastriatal injections of S100B, and brain sections were prepared 24 hours later. Scale bar = 100 μm. C, D. Quantification of Iba-1 immunostaining intensity. n = 3, *P < 0.05 vs. vehicle, ^# P < 0.05 vs. S100B. E. Diagram shows the relative locations of S100B injection (green arrow) and photographs (red box). Note that the distance between photographic field and injection site iss much greater here than in the study using needle track injury alone as the stimulus (Fig. 1C). F. Confocal micrographs show immunostaining for MMP9 (green) show that the increase observed 24 hours after injection of S100B into striatum was attenuated in PARP-1^−/− mice. Scale bar = 20 μm; representative of n = 3.