Running to Forget

What do ice cream and running have in common? Consuming indulgence foods and running are two actions that typically achieve opposite results: ice cream leads to weight gain and running helps you lose it; high sugar intake is linked to diabetes, cholesterol, blood pressure, and heart disease, while exercise reduces those risks. Ice cream and running do have one thing in common though—both are self-soothing. In response to stress, many people find comfort in food, but some people find it in physical activity. They crave exercise. They simply must go out for a run. Running is often described as " self-medicating " and even addictive. In fact, mental health providers often " prescribe " it as an effective routine for coping with depression, stress, and anxiety. The beneficial effects of exercise are widely known but poorly understood. The National Institute of Health recently released a series of calls for studying how exercise affects the body. This initiative seeks researchers that will identify the molecular transducers of physical activity. The goal is to deline-ate a molecular map to help us understand how physical activity transforms into wellbeing. One potentially important molecule is the brain-derived neurotrophic factor (BDNF) of the neurotrophic family of signal-ing proteins. Studies examining exercise in humans and rodents (running on treadmills or swimming) found elevated levels of BDNF (Heijnen et al., 2015). In fact, BDNF appears to be the molecular harbinger of wellbeing. Mitigating cognitive decline, mediating learning and memory, protecting against neuronal death, and encouraging growth of new neurons (Park and Poo, 2013; Weinstein et al., 2014) are only some of BDNF's ascribed beneficial functions. A study by Asthana and colleagues (Asthana et al., 2016), recently published in this journal, reported another possible role for BDNF, which may at first glance appear coun-terintuitive—the ability to forget. Asthana et al. (2016) investigated whether the BDNF val66met polymorphism (rs6265) plays a role in the ability to prevent fear memories from resurfacing. Memory reconsolidation is the processes in which reactivated long-term memories reenter a state of temporary instability where they are susceptible for disruption (Nader et al., 2000; Sara, 2000). Reconsolidating memories are sensitive to amnesic agents (such as protein synthesis inhibitors, brain insult, etc), which could prevent memory restabilization and persistence. Even without such invasive manipulations, reconsolidation may allow for memory update with information accessible at the time of retrieval (Monfils et al., 2009; Schiller et al., 2010). Asthana …