Microglial morphology in immature and juvenile hippocampus 3 d after SE. Representative Iba1 immunostaining images of hippocampus for a P9 (A-B) and a P21 (E-F) control rat, and a KA-treated P9 (C-D) and P21 (G-H) rat 3 d after SE, and those of the basomedial amygdala of a control (I) and a KA-treated (J) P21 rat 3 d after SE. The box in the CA1 region in A, C, E, and G is shown with a higher magnification in B, D, F and H, respectively. Note the morphological changes in microglia in the CA1 region (arrow, G) with more pronounced Iba1 immunoreactivity and thickened processes in the KA-treated P21 rat, and the lack of change in P9 rats. Note also the morphological changes of the microglia in amygdala of the P21 rat. Abbreviations: C, control; KA, KA-treated; P, postnatal. Scale bars: 1 mm in A, applicable also for C, E and G; 50 μm in B, applicable also for D, F, H, I and J.