FTY720 reduces microgliosis in CA3 region after icv injection of kainic acid (KA). Representative photomicrographs of ipsilateral hippocampal coronal sections of KA-treated (A), KA + FTY720-treated (B) and control (C) animal groups, immunostained with anti-Iba1 antibody (bright field microscopy). Images on the top of each panel are low magnification photomicrographs showing the entire ipsilateral dorsal hippocampus (scale bar 1 mm). The black frame represents the size field used for counting Iba1+ microglial cells in the CA3 region. Images on the bottom of each panel illustrate the area used for microglial cell counting (scale bar 100 μm). (D) Quantification of the number of Iba1+ microglial cells at CA3 region in control, KA-treated and KA + FTY720-treated animals. Three fields per slice were used to cover the CA3 region and to count the Iba1+ microglial cells at the site of injury, and a total of three slices per animal were analysed. Data are expressed as the mean ± SEM of positive cells in ipsilateral CA3 region per slice (control: n = 2; KA and KA + FTY720 n = 9 from three independent sets of experiments). Student’s t test: *P < 0.05 and **P < 0.01 vs control; #
P < 0.05 vs KA.