The Yin and Yang of Dopamine (IMAGE) University of California - Berkeley Caption UC Berkeley researchers have discovered that the brain neurotransmitter dopamine has a yin-yang personality, mediating both pleasure and pain. Credit Christine Liu graphic Usage Restrictions None License Licensed content 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.