Systemic TNFα increases IL-1β, NF-κB, and MCP-1 expression in TNFR1/R2+/+ (WT) mice. TNFR1/R2+/+ (WT) and TNFR1/R2−/− (KO) mice were injected with saline or TNFα (0.25 mg/kg) intraperitoneally. Brain mRNA expression of IL-1β and NF-κB-p65 and MCP-1 protein content were measured using real-time PCR and ELISA 1 h following saline or TNFα treatment. (A) Brain mRNA expression of IL-1β and NF-κB-p65 is increased by systemic TNFα in wild type mice, but not in TNFα receptor double KO mice. (B) Systemic TNFα administration increases brain MCP-1 protein in WT mice, but not in TNFR-KO mice. The results are the means ± SEM of two independent experiments performed with six mice for each treatment. *P < 0.05, **P < 0.01, compared to the corresponding saline control mice.