Conducting an animal study, researchers at the University of Missouri have gained significant insights into the brain circuit that controls binge eating.
The researchers found that deactivating the basolateral amygdala, a brain region involved in regulating emotion, specifically blocked consumption of a fatty diet in a rat.
However, they were surprised to see that deactivating the same brain region did not stop the rat from wanting to look for the food repeatedly.
"It appears that two different brain circuits control the motivation to seek and consume," said Matthew Will, assistant professor of psychological sciences in the MU College of Arts and Science and investigator in the Christopher S. Bond Life Sciences Center.
"Understanding how this circuit in the brain works may provide insight into the exact networks and chemicals in our brain that determine the factors influencing our feeding habits," he added.
Will and his colleagues point out that the release of opioids, pleasure chemicals that can lead to euphoria, into the brain produces binge eating in non-hungry rats.
Their study has shown that deactivating the basolateral amygdala blocks this type of binge eating.
"A key to curbing the obesity epidemic in America is controlling the desire to binge eat. Humans have more programming to start and continue eating than to stop eating, especially when they have a bowl of ice cream in front of them. Most of us would finish it even if we weren't hungry," Will said.
He said that the fact that deactivating basolateral amygdala had no effect on feeding in rats that were simply deprived of food for 24 hours suggested that this brain region is specifically involved in the overconsumption of food based on its palatability or pleasure driven by opioids, rather than the level of hunger.
"The finding that the basolateral amygdala only appears involved in the opioid produced consumption was the most surprising part of the study. Normally, if a rat stops eating, they will go lay down and take it easy. In this case, they showed all signs of still wanting to eat, but didn't," Will said.
A research article describing the study was published in August in Behavioral Neuroscience.