Air Date: Week of October 6, 2006

Scientists have discovered the link between the hunger-sensing part of the brain and the region responsible for emotional and addictive behavior. Jennifer Percy reports.

Transcript

PERCY: I just ate half the carton of fudge brownie ice cream. I really shouldn’t eat more. Oh, but those little chunks of fudge taste so good. Maybe I should have one more little spoonful. Oh, another one wouldn’t hurt. Maybe just two more…

[SCIENCE NOTE MUSIC STARTS]

PERCY: Have you ever kept eating and eating, knowing you should stop? Scientists at Brookhaven National Laboratory have identified the brain pathways that motivate our desire to overeat, linking them to the regions of our brain responsible for emotional and addictive behaviors.

To view these pathways, researchers implanted a device into the stomachs of seven obese patients. When the device was turned on it stimulated the stomach to expand and release the peptides responsible for telling the brain whether or not the body is full. The scientists compared scans of the patient’s brains when the device was turned on and off. They found that when the device was on, there was a significant increase of activity in the regions of the brain most closely associated with emotion. Most of that activity occurred in the hippocampus, an area of the brain linked to emotional behaviors, learning, memory and sensory impulses.

The study also shows that eating triggers the same part of the brain that is responsible for addictive behavior. This creates a desire to eat more and more even when we are full. The study is the first direct evidence that brain regions are involved in our physical response to eating. So the next time you find yourself reaching for that second slice of cake, don’t let your stomach do the talking, it might be telling your brain something else.

That’s this week’s note on emerging science. I’m Jennifer Percy