Enhanced pro-inflammatory profile in the aged brain. Hippocampal expression of TNFα (A), NOS2 (B) and IFNγ (D) mRNA was significantly greater in aged rats (*
P < 0.05; Student’s t-test; n = 5 to 15). Age was also associated with an increase in HMGB1 (C) protein expression in hippocampal tissue (**
P < 0.01; Student’s t-test; n = 5 to 7). For mRNA data, values are presented as means (±SEM) and expressed as a ratio to β-actin mRNA. HMGB1, high-mobility group protein B1; IFNγ, interferon-γ; NOS2, nitric oxide synthase; RQ, relative quantities; TNFα, tumour necrosis factor-α.