Interactions between the nervous and immune systems shape our capacity to learn and remember. My laboratory studies the cellular and molecular basis of a common, but poorly understood phenomenon. Aging significantly increases brain vulnerability to negative life events, and mental function in older individuals often declines sharply after events (e.g., infection or injury) that trigger activation of the immune system. Even when this decline is temporary, it is associated with a increased risk of developing, or accelerating Alzheimer's disease or other dementias. By exploring the mechanistic origins of this acute memory failure, and its relationship to neurodegenerative disorders, these studies may ultimately lead to strategies for improving cognitive resiliency, and for early treatment of some forms of cognitive decline.