Body's Brain Link to Hunger Identified

[Guest guest]

http://tinyurl.com/nybpp

In a report published in the July 20 issue of Neuron, researchers

tested the effect of several drugs that alter serotonin levels in the

brains of mice. They found that serotonin activates some neurons and

melanocortin-4 receptors, or MC4Rs, to curb appetite, and at the same

time blocks other neurons that normally act to increase appetite.

" This is more data that suggests that the melanocortin pathway is a

key pathway in your brain that affects food intake, body weight and

glucose, " said lead researcher Dr. Elmquist, a professor of

internal medicine at the University of Texas Southwestern Medical

Center at Dallas, and director of the Center for Hypothalamic

Research. " Our data suggest that serotonin is involved in affecting

this pathway. "

This dual effect helps explain how such drugs cause weight loss. The

findings also reinforce the role of serotonin, which regulates

emotions, mood and sleep, in affecting the brain's melanocortin

system, a key pathway that controls body weight, he said.

Learning how these drugs work, one could potentially target these

pathways and avoid the harmful side effects associated with a drug

like Fen-Phen while still controlling the feeling of hunger, Elmquist

said.

One expert agrees that it may be possible to develop new safe and

effective diet drugs, but for use only as a bridge to lifestyle changes.

" This finding really shows us where we can focus our efforts for new

therapeutics that target the receptor they have identified as the one

that's key in the regulation of food intake, " said Philip ,

director of the Division of Diabetes, Endocrinology and Metabolic

Diseases at the National Institute of Diabetes, Digestive and Kidney

Diseases.

thinks that these new drugs could target centers of the brain

that effect behavior. " The key is what motivates behaviors like

overeating and smoking, " he said. " Drugs that target the pathways

found in this study are likely to target motivational pathways that

are involved with serotonin. "

But drugs alone aren't the answer to the growing obesity epidemic,

said. " The only hope is that we actually modify lifestyle, " he said.

" The question is, can we find drugs that will help enable that? Not

something that would be a lifetime drug. But just like a nicotine

patch, one could imagine a patch that would get you through the

hardest part of losing weight so that you could actually change your

lifestyle, and you are not constantly fighting the urge to eat, "

said. " It is lifestyle change that will really make a dent in the

obesity epidemic. "

--Diane