Dopamine (DA) is a neurotransmitter, a biochemical molecule that allows communication within the nervous system, and one that directly influences behavior. Dopamine enhances the usually beneficial actions such as eating a healthy food by causing the sensation of pleasure thereby activating the reward / strengthening system. It is therefore indispensable to the survival of the individual. More generally, it plays a role in motivation and risk-taking in mammals, therefore in humans. This molecule is also involved in some abstract pleasures like listening to music.
Dopamine also plays other roles in the animal kingdom. In insects, especially the Drosophila fly, dopamine is involved in the creation of the exoskeleton.
This molecule belongs to the group of catecholamines, and is derived from two amino acids tyrosine or phenylalanine. In the central nervous system, it activates the postsynaptic and presynaptic dopaminergic receptors (D2 autoreceptor). It is mainly produced in the black matter and in the ventral tegmental area, situated in the midbrain (upper part of the brainstem). Although dopamine, with norepinephrine and serotonin, are very small in the brain, since together they concern less than 1% of neurons>, they play an essential final modulatory role of motor and psychic outputs.