Snyder, Solomon H.

   (1938–)

   A pioneer of the study of brain receptors and the binding of psychiatric drugs to them, Snyder was born in Washington, D.C., his father a cryptographer for the National Security Agency. After earning his M.D. at Georgetown University in 1962, between 1963 and 1965 he worked in the laboratory of pharmacologist Julius Axelrod (1912–) at the National Institute of Mental Health, where he acquired basic knowledge of molecular biology. Still intent upon becoming a psychiatrist, in 1965 he began training at Johns Hopkins University while lecturing there in the department of pharmacology. Snyder remained at Hopkins with his primary appointment in pharmacology, yet seeing psychiatric patients and supervising residents. From the late 1960s on, Snyder and co-workers in his laboratory made a number of important discoveries that opened up the field of receptorology. In 1972, wishing to do something to help out in the nation’s "war on drugs," they tried to find the target of opiates in the brain using binding approaches (attempting to find a "ligand," or radiolabeled drug, that binds to a given receptor). In 1973 Snyder and Candace Pert (1946–) discovered the opiate receptor (in research published in the Proceedings of the National Academy of Sciences), and shortly thereafter the two of them and others were able to identify agonists and antagonists of the receptor (in work published in 1973 in Science). Given that the properties of the opiate receptor "seemed very much like those of neurotransmitter receptors," as Synder later said, "we employed similar reversible ligand binding techniques to identify receptors for most of the major neurotransmitters in the brain, including those for dopamine [1975], alpha adrenergic [1976], . . . and serotonin [1975]." Julius Axelrod said of this work, "He revolutionized the field by using radioactive ligands of high specific activity to measure the binding constants of ligands to receptors. The grind and bind approach. . . . The whole field of receptorology exploded" (Healy, Psychopharmacologists, I, p. 42). His work on nitric oxide as a neurotransmitter, culminating in an article in Science in 1992 on "nitric oxide as a mediator of penile erection," helped lead to the drug sildenafil (Viagra) for erectile dysfunction.