Dopamine is one of the many chemical substances which acts as a neurotransmitter in the brain. Noradrenaline, adrenaline, serotonin, and acetylcholine are other neurotransmitters. There is a direct relationship between deficiency of a specific neurotransmitter and neuronal problems such as Parkinson's disease. L-dopa (levodopa) is a direct precursor of dopamine and is prescribed for the treatment of Parkinson's disease.
A molecule of dopamine. © lecerveau-mcgill.ca