Dopamine is an important neurotransmitter. One of the primary “pleasure chemicals” in the brain, dopamine is found in areas of the brain linked to experiences of joy and reward. In addition, dopamine pathways play a role in carrying signals related to attention, movement, problem solving, and pleasure. Brain chemistry blogs that discuss dopamine and other neurochemicals include BrainBlogger and Neurotopia.
The dopamine-rich nucleus accumbens is a significant site of action for addictive drugs. Chronic exposure to cocaine in lab rats produces a characteristic supersensitivity of the dopamine receptors found there. Evidence of abnormally low levels of dopamine is found in patients suffering from Parkinson’s disease, a finding that led researchers to an effective treatment for that disorder. Conversely, scientists learned that too much dopamine was at the heart of addiction to stimulants like amphetamine and cocaine.