Figure 3
Microglial activation in the mouse hippocampus following acute inflammation; effect of B 1 receptor antagonism. Effect of systemic administration of E. coli LPS (450 μg/kg, i.p., 24 h) on microglial activation (CD68-positivity) in the hippocampus of mice submitted to a previous 5-min forced swimming session. Mice were treated with imipramine (10 mg/kg i.p.) or SSR240612 (5 mg/kg, i.p.), given 30 min beforehand. (a) Representative image of CA1, CA2, CA3 and dentate gyrus (DG) subregions of hippocampus (Scale bar = 200 μm, original magnification, × 40). (b) Graphic representation on the average number of CD68-positive cells per field, determined in the CA1, CA2, CA3, and DG subregions of the hippocampus. (c) Representative images of CD68 immunohistochemistry in the DG subregion of hippocampus (Scale bar = 50 μm, original magnification, × 400) from pre-stressed animals treated with E. coli LPS, following imipramine (10 mg/kg i.p.), SSR240612 (5 mg/kg, i.p., 30 min or 10 mg/kg, p.o., 1 h), or saline 30 min before. LPS treatment showed an increase in the number of CD68-positive cells (c, arrows) in the hipocamppus, and SSR240612 (5 mg/kg, i.p., 30 min or 10 mg/kg, p.o., 1 h), was able to reduce this increase (c). Each column represents the mean of 4 animals and the vertical lines show the SEM. *P < 0.05, **P < 0.01 and ***P < 0.001 compared to vehicle-treated mice.