Figure 8.

RSD-induced macrophage recruitment to the brain and anxiety-like behavior required expression of CCR2 and CX₃CR1. WT and CCR2^KO or CX₃CR1^HET and CX₃CR1^KO C57BL/6 mice were subjected to six cycles of social defeat (RSD) or left undisturbed as controls (CON). Anxiety-like behavior was determined 14 h after RSD. Following behavioral testing, brains were collected for Percoll isolation of brain CD11b⁺ cells (n = 7–12, 4 independent experiments). A, Time to enter the open field. B, Total time spent in the open field. C, Representative flow bivariate dot plots of CD11b/CD45 labeling of Percoll-isolated microglia/macrophages. D, The percentage of brain macrophages. Bars represent the mean ± SEM. Means with asterisk (*) are significantly different from genotype CON (p < 0.05).