Figure 1.

Schematic representation of the consequences of microglial priming by neonatal infection or aging. Microglia are generally present as surveying, quiescent cells in the brain. Infection during the neonatal period and aging lead to priming of the microglia. Upon a subsequent inflammatory episode, such as systemic infection or other immunological challenges, the microglial response of the primed cells is exaggerated, leading to increased pro-inflammatory cytokine release. Ultimately the imbalanced inflammatory response ultimatley impacts CNS function that can lead to cognitive dysfunction and neuropathological changes associated with Alzheimer’s disease (AD) in the brain.