When a particular circuit in the brain is stimulated, it causes mice to voraciously gorge on food even though they are well fed, and deactivating this circuit keeps starving mice from eating, a new study shows.
The findings suggest that a breakdown within this neural network could contribute to unhealthy eating behaviors, the researchers said, although more work is needed to see whether the findings are also true of people.
The circuit lies in a brain area called the "bed nucleus of the stria terminalis" (BNST), and affects eating by inhibiting activity in another region, called the lateral hypothalamus, which is known to control eating, according to the study, published today (Sept. 26) in the journal Science
"Normally, there's a population of neurons in the lateral hypothalamus that's putting the brakes on eating," said study researcher Garret Stuber, a neuroscientist at the University of North Carolina at Chapel Hill. "But when you shut those cells down by stimulating this pathway, that releases the brake, and the animal starts to eat."
The lateral hypothalamus
has been known for more than 50 years to be an important part of the brain for controlling eating. Scientists had learned that putting stimulating electrodes in the lateral hypothalamus of animals would influence their eating behavior, but exactly how it works has been a mystery.