Mouse Study Identifies Neural Link Between Trauma and Binge-Eating Disorder

Research out of Virginia Tech has described how early life trauma can change a certain brain circuit and increase the risk of developing binge eating later in life. The mouse study could lay the foundation for prevention and early interventions for the eating disorder, which affects nearly 3% of Americans.

Binge-eating disorder is marked by recurring episodes of eating more rapidly than normal to beyond a feeling of fullness, and feelings of distress and loss of control, according to the Diagnostic and Statistical Manual of Mental Disorders. Eight in ten sufferers report childhood abuse, neglect, or other trauma.

“We wanted to know the mechanism underlying how early life trauma induces these eating disorders,” says principal investigator Sora Shin, an assistant professor with the Fralin Biomedical Research Institute at Virginia Tech, who is also an assistant professor in the Department of Human Nutrition, Foods and Exercise in the College of Agriculture and Life Sciences. “What we found is a specific brain circuit that is vulnerable to stress, causing it to become dysfunctional.”

Stress symptoms can affect our body, thoughts and feelings, and behavior. Shin and colleagues found that stress on mice who were separated from their litter mates may trigger life-long eating behavior changes. They traced this behavior to leptin, a hormone in the brain known to suppress appetite and weight gain by telling the brain it’s time to stop eating. In mice who experienced trauma and exhibited binge-eating behavior, leptin was less effective in a part of the brain called the lateral hypothalamus, where many behaviors are regulated. Without these signals from the brain, the overeating continued.

Digging deeper, the researchers identified neurons in another part of the brain called the ventrolateral periaqueductal gray that respond to the message from leptin and lateral hypothalamus, thereby regulating binge eating. Knowing the specific molecule and receptors in the brain to target can provide a foundation for developing therapeutic strategies for the disorder and understanding of the pathway could help in the prevention and early intervention of binge-eating disorder.

“This finding speaks to a set of broader health questions, which is how life’s health course is set based on certain early experiences,” says Michael Friedlander, executive director of the Fralin Biomedical Research Institute at VTC and Virginia Tech’s vice president for Health Sciences and Technology. “We are increasingly aware that early experiences and exposures ranging from those that occur even pre-conception in future parents through those that the fetus experiences in utero and to those that the child experiences throughout postnatal life can have dramatic impact on our health course throughout life. Dr. Shin’s latest discovery in this one particular case shines an important new mechanistic light on this process. Like all innovative research, the study also raises additional important questions such as whether and how these effects can be changed. Dr. Shin’s research can empower such lines of inquiry since a neural substrate and mechanism have been identified.”

The findings were published in Nature Neuroscience.