Microglia are stimulated to produce MCP-1/CCL2 before monocytes are recruited into the brains of BDR mice. A, B, Representative flow cytometry profiles from day 5 sham (A) and BDR (B) mice. The inserted number shows the percentage of total brain mononuclear cells that are CD45high CD11b+ (i.e., infiltrating monocytes). C, Solid bars represent the percentage of total brain mononuclear cells that are CD45high CD11b+ in day 5 sham and BDR mice. Hatched bars represent the total number of CD45high CD11b+ cells isolated from the brains of day 5 sham and BDR mice. Error bars represent mean ± SEM of data from 5 sham and 5 BDR mice, p > 0.05 versus sham mice. D, Solid bars represent the percentage of total brain microglia that express MCP-1/CCL2 in day 5 sham and BDR mice. Hatched bars represent the total number of cerebral microglia expressing MCP-1/CCL2 in day 5 sham and BDR mice. Error bars represent mean ± SEM of data from 5 sham and 5 BDR mice; *p < 0.05 versus sham controls.