The researchers said that the region of the brain was part of a larger region known as striatum. The researchers studied the effect of eating M&M chocolate sweets in mice and found that it increased the level of a natural brain chemical called enkephalin and when the researchers used a drug to stimulate the dorsal neostriatum into releasing higher levels of enkephalin, the mice ate more M&M chocolate sweets.
"This means that the brain has more extensive systems to make individuals overconsume rewards than previously thought.
The same brain area tested here is active when obese people see foods and when drug addicts see drug scenes. It seems likely that our enkephalin findings in rats mean that this neurotransmitter may drive some forms of over-consumption and addiction in people", lead researcher Dr Alexandra DiFeliceantonio said. The study has been published in the journal Current Biology.