Research

 

Drugs of abuse

Drug addiction involves a progressive loss of behavioral control. A major goal of our research is to determine how drugs impact the brain to produce compulsive drug-seeking behavior. Research has demonstrated that repeated intake of abused drugs such as cocaine and morphine not only alters the way those drugs are processed by the brain but can also alter the function of neural systems responsible for learning, motivation, and other aspects of behavioral control. We are particularly interested in developing and refining experimental methods for characterizing the behavioral consequences of repeated drug intake and applying these tools to identify and characterize neuroadaptations involved in the addiction process.

Food addiction

Obesity rates in the US and abroad have skyrocketed in recent decades. This obesity epidemic is fueled by changes that have occurred in the composition of the modern Western diet, as well as in the way this diet is consumed. While overeating — or consuming food beyond one’s energetic needs — is perhaps the most important proximal cause of obesity, much remains unknown about the distal factors responsible for overeating. Importantly, the loss of behavioral control associated with overeating has much in common with that observed in drug addiction, suggesting that these disorders may be mediated by common neurobehavioral mechanisms. We are currently investigating if consuming highly palatable and highly processed foods can have long-lasting effects on the way such foods are pursued and consumed, and whether these behavioral effects are related to adaptations in the neural circuitry underlying motivated behavior.

Decision making across the lifespan

Several of the neurochemical systems implicated in reward-motivated decision making are known to undergo major changes during development. Chief among these are the dopamine system and the endogenous opioid systems, which are each critical for important aspects of reward-motivated behavior. We are currently studying how age-related changes in the function of these neurochemical systems contribute to changes in the way goals are selected and pursued as we pass from adolescence to old age.