When Brendan Tunstall, PhD, looks at the science of addiction, he sees something missing.
“For all we’ve learned about the pharmacology and neurobiology of alcohol use disorder,” he said, “in preclinical behavioral research, historically, we’ve largely ignored one factor known to powerfully influence human behavior—other people.”
Dr. Tunstall, assistant professor of Pharmacology in the College of Graduate Health Sciences at the University of Tennessee Health Science Center, has built his research career around studying alcohol and substance use disorders. Now, with a $2.4 million award from the National Institute on Alcohol Abuse and Alcoholism (NIAAA), he’s leading an ambitious new project to understand brain mechanisms that could help us understand how social context interacts with alcohol use.
The project, “Dissecting the Neurobiological Basis of Social Control over Alcohol Self-Administration,” centers on a deceptively simple idea: most people drink in social settings. The influence of social context is well known to be complex, reported as both encouraging or discouraging alcohol drinking in humans, depending on the specific situation.
For example, binge-drinking behavior in young people is in part driven by the pleasure or fun associated with alcohol drinking, and can be facilitated by interaction with others (e.g., peer pressure to initiate alcohol drinking or drinking games that encourage rapid and high volume alcohol consumption). Quite oppositely, in someone with a long history of heavy alcohol consumption (i.e., in alcohol dependence), more persistent drinking can be motivated mainly by seeking relief from stress and other unpleasant emotions. In this case, withdrawal from social interaction could actually signal a worsening of the disorder. In fact, drinking despite the problems it causes with family or friends is a symptom that helps diagnose Alcohol Use Disorder.
“Preclinical addiction research offers us a chance to tease apart the biological basis of these kinds of complex interactions between social context and alcohol-motivated behavior,” Dr. Tunstall said, “but we are yet to completely capture this complexity.”
Dr. Tunstall’s lab is developing a rodent model that allows the study of alcohol use in both social and solitary settings, systematically manipulating the social variable. Using classic pharmacology and neurohistochemistry techniques, in combination with newer tools like optogenetics and CRISPR-Cas9 gene knockdown, his team will identify the brain circuitry that is unique to alcohol-seeking behavior in social contexts, determine how alcohol dependence might change this brain circuitry, and identify the role of the brain’s oxytocin system in modulating these processes. Oxytocin is a neuropeptide well-described as being important for the formation and maintenance of social bonds in humans and rodents alike.
By the end of the project, Dr. Tunstall hopes to do more than fill a research gap. He wants to redefine how scientists study, and eventually treat, alcohol use disorder.
“If we can understand how social connection and alcohol use interact in the brain, we may uncover new ways to help people get problem alcohol drinking behavior under control. It can be difficult to change this behavior, and to help people effectively, we need to leverage every tool available to us,” he said. “I hope this research can inform better pharmacological and social approaches to supporting recovery.”