Aging sensitizes rapidly isolated hippocampal microglia to LPS ex vivo

The present study tested whether aging sensitizes hippocampal microglia to a pro-inflammatory challenge ex vivo. Hippocampal microglia from 3 and 24 mo old male F344 × BN F1 rats were exposed to LPS (0, 0.1, 1, 10 and 100 ng/ml) ex vivo. 2 h post-LPS challenge, gene expression of microglial activation markers and cytokines were assessed. 24 mo old animals exhibited a potentiated pro-inflammatory cytokine (IL-1β and IL-6) response to LPS and increased levels of CD11b, Iba-1 and MHCII irrespective of LPS treatment. The present results demonstrate that aging sensitizes hippocampal microglia to pro-inflammatory challenges.