According to researchers at the University of Iowa, the loss of a gene linked to eating disorders in humans could possibly lead to several behavioral abnormalities that resemble behaviors observed in people with anorexia nervosa.
In a study on mice, scientists found that lacked the estrogen-related receptor alpha (ESRRA) gene were less motivated to seek out high-gat food when they were hungry and had abnormal social interactions. The effect of this was seen to be stronger in female mice who showed an increase in obsessive-compulsive-like behavior.
Additionally, the study discovered that ESRRA levels are controlled by energy levels. By restricting calorie intake to 60 percent of normal over several days, levels of ESSRA significantly decreased in the brains of mice.
"Decreased calorie intake usually motivates animals, including humans, to seek out high-calorie food. These findings suggest that loss of ESRRA activity may disrupt that response," Michael Lutter, assistant professor of psychiatry at the UI Carver College of Medicine, said.
Both anorexia nervosa and bulimia nervosa are common and severe mental illnesses. About 50 to 70 percent of the risk of having an eating disorder is based on inheritance. However, identifying the gene that predicts this has been difficult in the past.
"This work identifies estrogen-related receptor alpha as one of the genes that is likely to contribute to the risk of getting anorexia nervosa or bulimia nervosa," Lutter said. "Clearly social factors, particularly the western ideal of thinness, contribute the remaining 'non-genetic' risk, and the increasing rate of eating disorders over the past several decades is likely due to social factors, not genetics."
In order to fully understand the effects of ESRRA, researchers selectively removed the gene from particular brain regions associated with eating disorders. By removing the gene from the orbitofrontal cortex, mice were less willing to work for food when hungry.
The new findings point to treatment directed at particular neural circuits for eating disorders.
Source: Medical Xpress
