The microglial activation in the hippocampus of KA-icv-injected mice. CD-1 mice received KA-icv-injections and were sacrificed at day 1, 3, 5, and 7 post KA-injection (KA-d1, KA-d3, KA-d5, KA-d7). For control, the mice were sacrificed at day 7 post vehicle-injection (veh). The microglial activation in the ipsilateral side of CA1, CA3, and DG was examined by immunostaining with anti-Iba-1 (red) and anti-GFAP (green) antibodies. Cell nuclei were stained with Hoechst 33258 (blue). The representative images of the ipsilateral side of CA1, CA3 and DG area are shown (a). The location of pyramidal layer (Py), striatum radiatum (SR). Molecular layer (Mo), and Hilus (Hi) are indicated in the left lane of the panels. The IR of GFAP (b) and Iba-1 (c) in 250 μm × 250 μm field in CA1 (white columns), CA3 (gray columns) and DG (black columns) were calculated. The results are the mean ± S.D. from 8 images. Significant differences between the control (veh) and the KA injection are indicated by *, P < 0.05; **, P < 0.01; ***, P < 0.001. Significant differences between day 1 post KA injection and day 3 post KA injection in panel d are indicated by #, P < 0.05; ##, P < 0.01.