Researchers identified a reward-related neural circuit that controls compulsive sugar consumption in mice without removing their will to eat for survival purposes.
The findings could provide a target for safe new treatments for humans who have a tendency to compulsively overeat, Cell Press reported.
"Although obesity and Type 2 diabetes are major problems in our society, many treatments do not tackle the primary cause: unhealthy eating habits," said senior study author Kay Tye of the Massachusetts Institute of Technology. "Our findings are exciting because they raise the possibility that we could develop a treatment that selectively curbs compulsive overeating without altering healthy eating behavior."
Compulsive overeating is similar to the reward-seeking behavior seen in drug addiction, but the big difference is that eating is necessary for survival. The need to eat makes treating these compulsive behaviors more difficult than other addictions.
A research team suggested a neural pathway from the lateral hypothalamus to the ventral tegmental area could be to plain for compulsive overeating because it is involved in other reward-seeking behaviors such as sex.
To test this idea the researchers used a technique called optogenetics, which involved genetically modifying certain neurons to express light-sensitive proteins the control neural excitability, delivering light to switch these cells either on or off. Through this technique the researchers found activation of the pathway from the lateral hypothalamus to the ventral tegmental area prompted well-fed mice to spend more time feeding and seek out sugar rewards more often. On the other hand, inhibiting this pathway decreased food consumption in hungry mice
"In our modern day society, there is no scarcity of palatable foods, and high-sugar or high-fat foods are often even more available than fresh produce or proteins," Tye said. "We have not yet adapted to a world where there is an overabundance of sugar, so these circuits that drive us to stuff ourselves with sweets are now serving to create a new health problem. The discovery of a specific neural circuit underlying compulsive sugar consumption could pave the way for the development of targeted drug therapies to effectively treat this widespread problem."
The findings were published in a recent edition of the journal Cell.
