Figure 7.

Repeated social defeat enhanced c-Fos activation, but did not affect behavior or microglial activation in IL-1r1^−/− mice. Male IL-1r1^−/− C57BL/6 mice were subjected to six cycles of SDR. A, Representative pictures of c-Fos staining from MeA (20×). B, Average number of c-Fos-positive cells in the MeA (n = 5). C–F, In a separate set of studies, WT or IL-1r1^−/− C57BL/6 mice were subjected to repeated social defeat and light/dark preference was determined 14 h after the sixth cycle of social defeat. C, Average time to enter the dark zone. D, Average time spent in the dark zone (n = 6–8). Following behavioral testing, mice were perfused and brains were collected for Iba-1 immunohistology. E, Representative images of Iba-1 staining from MeA (40×). Insets include enlarged image of Iba-1⁺ cell indicated by arrow. F, Proportional area for Iba-1 staining in the MeA (n = 3). Bars represent the mean ± SEM. Asterisks indicate significant differences within the genotype (p < 0.05). n.s., Not significant.