Effect of LPS on activation of astrocytes (A) and apoptotic cell death (B). Mice were injected intraperitoneally with either 250 μg/kg LPS or sterile saline (0.9% NaCl) daily for 7 days before sacrifice. Forty μm-thick sections of brains from mice were immunostained with rabbit polyclonal anti-GFAP antibody for evaluation of activation of astrocytes. The broad distribution and deep intensity of GFAP reactive cells increased in the LPS injected mice brain. Each panel is representative of 6 animals. Apoptotic cell death was determined by DAPI staining and TUNEL assay. Apoptosis (%) was defined as the percentage of the number of TUNEL-positive cells per surface of unit. Values are mean ± S.E. (n = 6). *P < 0.05 indicates significantly different from LPS-treated cells.