According to the National Institutes of Health (NIH), in 2013, 16.5 million Americans reported heavy drinking of alcohol; 55.8 million were current cigarette smokers; and 24.6 million were current illicit drug users. Abuse of tobacco, alcohol, and illicit drugs exacts $700B annually in costs related to crime, lost work productivity, and healthcare. A closely related national health problem involves 4.2% of females who endure bulimia nervosa, while up to 5% of Americans experience binge eating disorder. Dr. Mark West, Professor of Psychology at Rutgers University, uses animal models to study the neural bases of cocaine addiction, for which there is no FDA-approved medication, and binge eating. Understanding the neural mechanisms and cognitive or emotional processes associated with these disorders could help identify both the changes in the brain resulting from addictive behaviors as well as therapies to help millions of affected individuals combat them. Treatment strategies are improving, and the goal of Dr. West’s research is continued improvement through better understanding of the underlying mechanisms.

Fortunately, scientific advances have revealed where brain mechanisms are likely to be found. Addictive psychological disorders involving substance abuse and binge eating are acquired because these activities trigger heightened dopamine release in the brain’s reward/motivation system. The natural and original functioning of dopamine in this system promotes survival by enabling organisms to learn behaviors that earn rewards such as water, food, or sexual stimulation. Rewarding particular behaviors via dopamine release onto neurons of this system enhances the motivation to repeat them, by helping the brain learn and remember where it found the reward. Such a system is built to change with experience via dopamine-mediated alterations that promote learning, which are under intense investigation. As drugs and binge eating over-stimulate dopamine’s actions, resulting in motivation to repeat those behaviors, identifying how the reward/motivation system operates and how it changes with over-stimulation will provide powerful insights into developing a treatment target.

To this end, Dr. Mark West and his team study animal models to understand the brain during behavior by recording activity at the level of the single neuron in these related areas of research:

• Drug Abuse and Cocaine Addiction: Drugs of abuse overstimulate dopamine transmission, especially in the developing brain of a teenager that is more susceptible to change. Dr. West and his team have found that neurons in the dopamine reward/motivation system acquire a response to drug cues, and also that activity of these neurons is directly related to drug level in the brain. The team hopes to further characterize these patterns so that they can become targets of medicines and behavior therapies.
• Opiate Addiction: In response to the ongoing opioid epidemic, he has teamed with another Rutgers researcher to study fentanyl self-administration in both laboratory animals and humans. They will test whether excessive avoidance behavior is a result of, or predisposes people to, chronic opioid self-medication.
• Binge Eating: Very similar to the action of an addictive drug, over-consumption of sweet, fatty foods also overstimulates dopamine transmission to a greater degree than a normal meal. Using the same single neuron recording methods used to study drug abuse and cocaine addiction, Dr. West and his team are studying the effects of a history of binge eating on the dopamine reward/motivation system, and how neural patterns of the system change in response to rapid overconsumption of high calorie food.