September 9, 2009

Two brain circuits control desire for food

U.S. scientists say they have determined two different brain circuits might control the motivation to seek food and then consume it.

University of Missouri researchers using laboratory rats said they discovered deactivating the basolateral amygdala -- a brain region involved in regulating emotion -- specifically blocked consumption of a fatty diet. Surprisingly, it had no effect on the rats wanting to repeatedly look for food.

It appears that two different brain circuits control the motivation to seek and consume, said Assistant Professor Matthew, who led the study. Understanding how this "¦ works may provide insight into the exact networks and chemicals in our brain that determine the factors influencing our feeding habits.

The scientists said release of opioids -- pleasure chemicals that can lead to euphoria -- into the brain produces binge eating in non-hungry rats. Will and his team determined deactivating the basolateral amygdala blocked that type of binge eating but had no effect on feeding in rats that were simply deprived of food for 24 hours.

That discovery, Will said, suggests the basolateral amygdala is specifically involved in the overconsumption of food based on its palatability or pleasure driven by opioids, rather than the level of hunger.

The research was reported in the August issue of the journal Behavioral Neuroscience.