In a recent issue of The Neuroscientist, Jolie Barter, a graduate research assistant, and Thomas Foster, Ph.D., Evelyn F. McKnight Chair for Research on Cognitive Aging and Memory, examined the role of epigenetics in the process of brain aging and cognitive decline.
They looked at key questions regarding how epigenetic mechanisms — mechanisms that switch genes on and off — affect brain aging. In their review, Barter and Foster hypothesize that changes in neural activity during aging reduce the signaling for expression of genes that are important for cognitive processes, including memory. In turn, decreased gene activation leaves the DNA vulnerable to epigenetic modification, such as DNA methylation. The epigenetic modifications further inhibit the ability to activate genes that are required for maintaining a youthful brain. Importantly, epigenetic mechanisms interact with environmental and lifestyle factors including diet, exercise, stress and hormone levels. Barter and Foster hypothesize that this epigenetic-environmental link can explain how lifestyle factors and the history of experience can influence the rate of aging, the resilience or susceptibility to stressors of aging and determine the trajectory of cognitive decline.