Scientists Identify Brain Circuitry That Triggers Overeating

This article explains a new study suggesting that human eating disorders are cause by “faulty wiring” in BNST cells located in the amygdala. By focusing on the gaba neurons in the bed nucleus of the stria terminalis (BNST), the primal function of eating can potentially be stimulated from the bridge of BNST that forms between the amygdala and lateral hypothalamus. This theory was tested on mice where an opto-genetic technique was used to stimulate their BNST cells.  Fiber optic cables were implanted into the brains of the mice so the synapses of the BNST cells could be stimulated with a shine of light. However, because brain cells don’t typically respond to light, scientists used genetically engineered viruses to deliver light sensitive proteins derived from algae into the mice brains. I am not sure how, but those proteins then only get expressed in the BNST cells. Once in place, a light was shown through the fiber optic cables and onto the BNST synapses, and immediately the mice began to eat “voraciously” and even gave preference to high in fat foods, though they had full stomachs. This stimulation exhibited behaviors in the mice associated with reward and pleasure and shutting down the path way caused the opposite reactions. The next step for this discovery could be a possible development of a drug that could correct a malfunctioning BNST circuit.

This article is very interesting to me due to it very high relevance in my classroom instruction at the moment. Along with starting the neurology unit in our textbooks, our device design project may have a similar approach as it deals with targeting depression, a condition that is  just now being accepted as a possible physical disease. This discovery really pinpoints the exact region and mechanism that is failing to function properly in the brain and corrects this eating behavior using a very innovative approach. Maybe fixing chronic depression has a similar answer. I found the protein delivery method interesting, but not sure how it solely targets the BNST cell synapses. Also, on a broader scale, I feel that this is very important to the American populous as many young and even men suffer from eating disorders such as binge eating, purging, and anorexia. These conditions are serious, and because many people see them as psychological issues, no one really has ever thought about treating it as an actual disease. This evidence has really convinced me that coupled with outside influences eating disorders are really something going wrong with nerve communication. Maybe this explains obesity as well!

http://www.sciencedaily.com/releases/2013/09/130926142834.htm