The neostriatum, the part of the brain that controls movement, may also hold mechanisms that control consumption, such as over-eating and taking drugs.

An opium-like chemical produced in the brain, enkephalin, generates motivation to consume rewards, such as M&Ms. When injected into the neostriatum of rats, researchers found that they consumed twice the amount of sweet, fatty foods.

Finding the brain mechanisms for overconsumption may lead to designing better biological-based treatments for obesity and binge eating disorders.