Dopamine is used as precursor in the synthesis of the neurotransmitters, norepinephrine and epinephrine. Norepinephrine mobilizes the brain and body for action. Epinephrine plays a role in the fight-or-flight response, increasing blood flow to muscles, output of the heart, pupil dilation response, and blood sugar level. In the brain, dopamine functions as a neurotransmitter to send signals to other nerve cells. The brain has several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Nerve cells that produce dopamine facilitate the formation of declarative memories, a term for memories that can be consciously recalled. These memories can stay for a long time and are considered long-term memories.
In summary, dopamine positively affects attention, behavior and cognition, learning, memory, mood, movement, and pleasurable reward. It can also reduce carbohydrate cravings. Dopamine increases brain voltage.