Researchers Identify Neural Pathway that Controls Overeating

the Neurology Advisor take:

Researchers have discovered a reward-related neural circuit in a mouse model that controls binge eating. The discovery could have implications for treatment of obesity and eating disorders.

Kay M. Tye, PhD, of the Massachusetts Institute of Technology, and colleagues, confirmed that a pathway between the lateral hypothalamus (LH) and the ventral tegmental area (VTA) play a significant role in sugar addiction and overeating. The pathway is involved in other reward-related behaviors as well, including sex and drug addiction.

The researchers used optogenetics to control neurons sensitized to light. When the LF-VTA circuit was turned on in well-fed mice using color-coded cues, the mice overate and disregarded negative stimulation, even crossing an electrified metal platform to reach the sugar reward. When the pathway was inhibited, the compulsive sugar-seeking behavior was reduced but not food consumption in hungry mice. The results suggest that the LH-VTA pathway does not control appetite linked to hunger.

"We show that inhibiting the LH-VTA pathway reduces 'compulsive' sucrose seeking but not food consumption in hungry mice," the researchers wrote in the study, published in Cell. "We reveal that the LH sends excitatory and inhibitory input onto VTA dopamine and GABA neurons, and that the GABAergic projection drives feeding-related behavior."