It’s All In Your Head—Sweet Tooth ‘Circuit’ Discovered
Do you have a sweet tooth? Do you hanker for gooey goodies? Have a crush on candy? If so, you’re not alone. Health experts consider the obesity epidemic to be a major public health threat. For some overweight or obese people, compulsive overeating and sugar addiction are constant problems.
Like drug addiction, compulsive overeating is a type of reward-seeking behavior. There’s one important difference, though. Eating is necessary for survival, while taking drugs is not. Scientists are concerned that any treatments they may devise to short-circuit this sugar-addiction circuit may also eliminate the urge to eat at all. That would be just as bad as overeating oneself to death.
So they were encouraged, recently, when they discovered a neural pathway in the brains of mice that promotes excessive sugar consumption. Experiments indicated that this pathway is independent of separate pathways that ensure that hungry mice feed. By shutting down the sugar addiction pathway, investigators were able to influence sugar-seeking mice to stop going out of their way to get sugar. But the same mice didn’t stop eating altogether.
"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,” said senior study author Kay Tye, of the Massachusetts Institute of Technology, in a press release.
Tye believes these separate food-seeking brain circuits developed to ensure adequate feeding when resources are scarce. But modern life has thrown us a curveball. ”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,” said Tye. “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.”
Edward H. Nieh, Gillian A. Matthews, Stephen A. Allsop, Kara N. Presbrey, Christopher A. Leppla, Romy Wichmann, Rachael Neve, Craig P. Wildes, Kay M. Tye. Decoding Neural Circuits that Control Compulsive Sucrose Seeking. Cell, 2015; 160 (3): 528 DOI: 10.1016/j.cell.2015.01.003
Joshua H. Jennings, Randall L. Ung, Shanna L. Resendez, Alice M. Stamatakis, Johnathon G. Taylor, Jonathan Huang, Katie Veleta, Pranish A. Kantak, Megumi Aita, Kelson Shilling-Scrivo, Charu Ramakrishnan, Karl Deisseroth, Stephani Otte, Garret D. Stuber. Visualizing Hypothalamic Network Dynamics for Appetitive and Consummatory Behaviors. Cell, 2015; 160 (3): 516 DOI: 10.1016/j.cell.2014.12.026