Researchers led by San Diego scientists have created a lab-grown model of the anorexic brain using stem cells derived from patients with the eating disorder. They say the results provide further evidence for understanding anorexia as largely genetically based, rather than primarily as a socially conditioned behavior.
"There's a stigma regarding eating disorders — that it's something social," said UC San Diego researcher Alysson Muotri. "But in fact, our results point to a strong genetic factor. And moreover, it suggests there's a specific pathway in the brain that is altered."
For the study published Tuesday in the journal Translational Psychiatry, Muotri and his colleagues took skin cells from seven anorexia patients and then converted them into stem cells in the lab. They then coaxed those stem cells into brain cells, providing scientists with a new model for studying the eating disorder.
Muotri, who has developed similar models for other diseases, said the "disease-in-a-dish" approach is great for studying neurological disorders. Scientists wanting to study these diseases "can't just open the skull and look through the brain cells," he said.
The researchers compared anorexic brain models with other models built from cells taken from four non-anorexic people, most of them relatives of the anorexic patients. The researchers found a difference in the TACR1 gene between the two groups.
Muotri admits the number of patients studied was small, but says these results support "the idea that anorexia has a fundamental biological basis on the perception of fat in the body."
Anorexia experts not involved in the study told KPBS this is another step toward understanding the underlying biology of a misunderstood and often deadly disease.
Walter Kaye, director of the UCSD Eating Disorder Research and Treatment Program, said in an email to KPBS that the findings establish an interesting link between anorexia and a genetic pathway known to play a role in anxiety and fat metabolism.
"This may be a very important clue to understanding puzzling symptoms in anorexia nervosa, such as why food is often associated with anxiety, and why patients see themselves as fat and tend to avoid fat-containing foods," Kaye wrote.
Christina Wierenga, co-director of the eating disorder research program at UCSD, wrote in an email to KPBS, "Although the sample size is small, this elegant study is the first of its kind to examine gene expression in neurons derived from individuals with anorexia and sheds new light on possible causes of anorexia. Of course, replication in larger samples is needed."
