Lipopolysaccharide promotes M1 pro-inflammatory cytokines and chemokine production by microglia and central nervous system-associated phagocytes sorted from mouse brain. Microglia and central nervous system (CNS)-associated phagocyte enriched cell populations were sorted according to CD11b and CD45 expression patterns, resuspended and incubated in culture medium for an additional 24 hours. Pro-inflammatory cytokines IL-1β, IL-6, TNFα and CCL2 chemokine were quantified by cytometric bead array. (A) Ex vivo stimulation with 0.5 μg/ml lipopolysaccharide (LPS) (black bars) compared to saline control (white bars). (B) In vivo stimulation by LPS injections in mice as described in Methods (black bars) compared to saline injections (white bars). Bars represent the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.005 versus saline control; n = 3-8. i.p., intraperitoneal.