Researchers at Johns Hopkins University are saying they have stumbled on a new type of nerve cell that may be telling laboratory mice when to stop eating a meal, and the new discovery may lead to controlling the obesity epidemic in the United States and other countries.

A press release from eurekalert.org says the research team was looking at proteins that strengthen and weaken synapses, or intersections, between the cells in the brains when they began to notice some significant weight gain among the mice on which they were conduction experiments.

Richard Huganir, Ph.D., director of the Department of Neuroscience at the Johns Hopkins University School of Medicine and graduate student Olof Lagerlöf, M.D., were focused on the enzyme OGT, which is a biological catalyst that is involved with a number of bodily functions, including sugar chemistry and the body’s use of insulin.  To study the effects, the team deleted the gene from the primary nerve cells in the hippocampus and cortex of adult mice, and they soon noticed the mice had begun to gain weight.

In a span of three weeks, the rodents had doubled in weight, despite eating the same number of meals as the mice in the control group.  The treated mice seemed to linger and eat longer meals and consumed more calories per meal.  When the extra food was taken away, they stopped gaining the extra weight, and this suggested to the scientists the mice were unable to tell when their bodies were full, leading to overeating.  The extra weight was found to be fat buildup, and not muscle mass in the mice.

“When the type of brain cell we discovered fires and sends off signals, our laboratory mice stop eating soon after,” commented Haganir.  “The signals seem to tell the mice they’ve had enough.”.

Lagerlöf added there were many things we still don’t know about this system, “but we think that glucose works with OGT in these cells to control ‘portion size’ for the mice. We believe we have found a new receiver of information that directly affects brain activity and feeding behavior, and if our findings bear out in other animals, including people, they may advance the search for drugs or other means of controlling appetites.”

Details of the study were published in the journal Science.