Brain illustration (IMAGE) University of California - Davis Caption The nucleus accumbens (represented in blue) is a part of the brain that controls motivation. Researchers from UC Davis compared samples of the nucleus accumbens in mice and humans to find clues to how this part of the brain is affected by stress and depression in males and females. Credit UC Davis Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.