Dopamine

   Dopamine is a neurotransmitter belonging chemically to the class of catecholamines.

   The efficacy of many antipsychotic drugs is thought to reside in their success in blocking the receptors for dopamine in the brain, especially the D2 receptor. In 1957, Swedish neuroscientist Arvid Carlsson (1923–) discovered the role of dopamine as a neurotransmitter, and his article appeared in Science in 1958. (For the basic scientific narrative in these neurotransmitter discoveries, see Iproniazid and the Monoamine Oxidase Inhibitors; Neurotransmitter; Reserpine.)

   In 1961, Julius Axelrod (1912–) and co-workers at the National Institute of Mental Health discovered a reuptake mechanism for norepinephrine (NE)—and for dopamine (as the precursor of NE, dopamine is also a neurotransmitter in its own right)— announcing the discovery in Science. (Axelrod won a Nobel Prize in 1970 for research that also included this work.)

   In 1975, Solomon Snyder and co-workers discovered the existence of a receptor for dopamine, making the announcement in Life Sciences. And the following year, 1976, the Snyder group announced in Science that the potency of antipsychotic drugs was a function of their ability to block this dopamine receptor. (Two months later, Philip Seeman [1934–], a pharmacologist at the University of Toronto, came forward in Nature with the very same discovery.) In 1976 as well, Snyder and colleagues ventured the "dopamine hypothesis" of schizophrenia in the American Journal of Psychiatry, using among other evidence the information that amphetamines, which are "dopaminergic" (i.e., potentiate the action of dopamine), made schizophrenia worse. Similar to the fate of the "catecholamine hypothesis" of depression, the dopamine hypothesis of schizophrenia is no longer strictly believed. Yet, it stimulated much important research on dopamine and its role in psychiatric illness.