NEW YORK, Mar 30 (Reuters Health) - By mapping neural circuits that lead to the brain's feeding control center, scientists hope to gather clues that might help in the treatment of obesity and eating disorders.

Specific sets of brain cells respond to hormones--among them two proteins called leptin and neuropeptide Y--that control eating behavior. Other areas of the brain that play a role in eating decisions have not been identified before now, according to Dr. Jeffrey Friedman of The Rockefeller University in New York.

Friedman and his colleagues tagged a virus that travels from brain cell to brain cell with a protein that glows and injected it into the feeding control center in the middle of the mouse brain, hoping to trace the green-glowing chemical to other areas that might influence eating behavior.

A surprising number of brain areas provided inputs to the feeding control center, including some regions not previously associated with eating behavior, the study authors report in the March 30th issue of Science.

The researchers believe that the feeding control center takes inputs from other areas and interprets them before sending signals to an as yet unidentified center that makes people decide to eat.

"Further studies including three-dimensional reconstruction of these images should reveal the precise nature of the connections to the hypothalamus (where the feeding control center is) from these brain regions," Friedman's team concludes.

"We believe that a fuller understanding of the neural systems that regulate feeding will be essential for an understanding of the (causes) of obesity and other disorders," Friedman told Reuters Health. "This could lead to the identification of new molecules that play a role in regulating food intake."

Friedman added that these findings make it clear "that feeding behavior is controlled by an interplay of basic drives (such as that from leptin) and other drives having to do with emotional state, sensory inputs such as smell, as well as drives perhaps relating to higher brain functions such as the conscious decision to eat less."

From ReutersHealth