Despite our growing knowledge of the health benefits of exercise, exercise participation among the general population is declining. Identification of the neural circuits controlling the initial acquisition and long-term maintenance of exercise behavior could lead to novel pharmacological and behavioral strategies to increase exercise behavior. Understanding these circuits could also provide new insights into the mechanisms underlying the many beneficial effects of exercise on mental health. We are currently focusing on the involvement of dopaminergic-striatal circuits in the acquisition and maintenance of voluntary exercise behavior in males and females.

Similar to stress-protective effects of exercise in humans, rodents allowed voluntary access to running wheels are protected against the development of anxiety- and depression-like behaviors produced by exposure to stress. Experiments in the lab aim to identify the features (e.g. duration, pattern, intensity, frequency, and controllability) of exercise important for eliciting stress protection, as well as the neuroadaptations in the brain that occur with exercise that contribute to these beneficial effects. We are currently investigating whether exercise-induced neuroadaptive changes in the nigrostriatal and mesolimbic dopamine systems are important for the anxiolytic and antidepressant effects of exercise.

Common therapeutic strategies for anxiety and trauma-related disorders target underlying fear memories. One way to overcome the effects of intrusive and persistent fear memories is by forming new competing memories through the process of fear extinction. We are currently investigating how behavioral and pharmacological manipulations, such as exercise, MDMA (ecstasy), and activation of midbrain dopamine neurons, can alter the molecular and cellular makeup of these competing fear and fear extinction memories. This information could contribute to our understanding of how fear and fear extinction memories are formed and stored in the brain and could lead to novel strategies for the treatment of anxiety and trauma-related disorders.

Stress-related disorders, such as anxiety, depression and drug abuse, are more common in females than males, yet females are understudied in neuroscience. We have observed that female rats are more responsive to the stress-protective effects of exercise than males. Accelerated stress resilience from exercise in females is a completely unexplored resilience phenomenon. We are currently investigating the neurobiological mechanisms underlying sex differences in response to exercise.