Representative photomicrographs of microglia (A to C, SN; D to F, striatum) in the rat brain after LPS injection. As shown by Iba1 immunostaining in the SN (A) and striatum (D), a few microglia at the resting status with a small rod-shaped soma and ramified processes (arrows indicated in A and D) were found in the control rat brain. Numerous activated microglia showing bright staining of an elongated or a round shaped cell body with blunt or no processes (arrows indicated in B and E) were observed in the SN (B) and striatum (E) of the rat brain with neonatal LPS exposure. Celecoxib treatment reduced the number of activated microglia stimulated by LPS in the above areas (C, F and G). The scale bar shown in A represents 50 μm for A to F. Quantitation of the number of Iba1+ cells (G) and the percentage area of image that contained Iba1 staining (H) in the SN and striatum were performed as described in Methods. The results are expressed as the mean ± SEM of six animals in each group, and analyzed by one-way ANOVA. *P <0.05 represents a significant difference for the LPS + Vehicle group as compared with the Saline + Vehicle group. #
P <0.05 represents a significant difference for the LPS + Celecoxib group as compared with the LPS + Vehicle group.