Dopamine

Dopamine is a compound which is present in the body as a neurotransmitter and a precursor of substances such as adrenaline. It is an organic chemical of the catecholamine and phenethylamine families. It plays an important role in the brain and the body. Its name is derived from its chemical structure. It is an amine synthesised by removing a carboxyl group from a molecule of its precursor chemical L-DOPA. It occurs in brain cells and adrenal cells. In the brain cells, it is transported to synaptic locations and packaged into vesicles for release that occurs during synaptic transmission. After its release, the dopamine that is free is either reabsorbed into the pre-synaptic terminal for reuse or it is broken down by the enzymes like monoamine oxidase or COMT. It produces a variety of degradation metabolites whose end products are eventually excreted in the urine. Our brain includes numerous dopamine systems and they play an important role in behaviour hat is reward motivated. Most rewards increase the level of dopamine in the brain and many addictive drugs increase dopamine neuronal activity. Other systems that are affected by dopamine are the motor control activities that control the release of several hormones.