fat-derived hormone rewires brain

Perhaps people should start blaming their brains instead of their diets for their weight. A hormone, leptin, known to control appetite, appears also to rewire the brain’s weight-regulation centers in early life, researchers from Oregon Health and Science University report in the April 2 Science. Secreted by fat cells in the body, leptin controls feeding behavior by suppressing appetite. Richard Simerly and colleagues studied mice that were genetically engineered to be unable to produce leptin, and therefore became obese. The researchers found that the animals had disrupted nerve connections in the part of the brain that controls eating, but that, when injected with leptin as babies, their brain circuits developed normally. “The same hormone that helps regulate food intake later in life also regulates the formation of weight-control brain mechanisms very early in life,” Simerly stated in a press release. He added that leptin’s role during brain development could have lasting effects on an individual’s ability to regulate his or her body weight.

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 4/06/2004.