Scientists discover brain circuits tied to overeating
New research shows that an area of the brain, when wired in a particular way, could lead to overeating, whether a person is hungry or not.
Researchers from the University of North Carolina School of Medicine said their study could provide insight into how obesity and eating disorders, such as anorexia and bulimia nervosa, could be partially caused by neurological factors.
This discovery adds to a finding 60 years ago that electronically stimulating brain cells in mice could cause them to eat when they were not hungry.
The new study, published in the journal Science, focused on a specific cell type called gaba neurons, which live in the nucleus of a part of the brain’s amygdala (the brain’s emotion center) called the BNST. Researchers activated BNST cells in the brains of specifically bred mice using a method involving fiber optic cables, genetically engineered proteins and light.
They found that even though the mice were well-fed before the experiment, they appeared unusually hungry and ate approximately half of their daily caloric intake in about 20 minutes after their BNST cells were stimulated. The researchers said the mice demonstrated an especially strong preference for high-fat foods.
The link between the BNST and overeating was further strengthened by the finding that when the BNST cells were de-activated, the mice didn’t seem to want to eat, even if they were food-deprived.
The study suggest that humans with “faulty wiring” in their BNST cells could have abnormal hunger cues, which could lead to people eating or avoiding food regardless of hunger levels, or it could lead to the development of eating disorders.