Levels of IL-1β, TNF-α and IL-6 measured by ELISA in cortex and hippocampus of 3- months old mice treated with one i.p. injection of LPS at 1mg/kg or saline (0.9% NaCl) and sacrificed after 3 hours. Cytokine levels are expressed in pg/mg of protein. Results are±SEM of 3 mice per group. ND: not detectable, under the limit of detection.