What were Solomon Snyder's contributions to neuroscience and pharmacology?

Answer: Solomon Snyder is best known for his development of an assay to measure the binding of chemicals to receptors, particularly the opioid receptors.

solomon snyder opioid receptor pharmacology

Solomon Snyder is an American neuroscience and pharmacology researcher who conducted research out of the Johns Hopkins School of Medicine. His main research interest is in using biochemical methods to determine the properties of receptor-ligand interactions. 

In collaboration with Candace Pert, Snyder developed an assay using a radioactive version of a chemical that is known to produce a psychoactive active effect, then washing the chemical over a preparation of brain tissue and guinea pig intestine. It is known that ligands bind reversibly, and that when two ligands are present, they have the ability to compete with each other for binding to the active site. By exposing brain tissue to both solutions at the proper concentrations, they are able to measure the radioactivity signal given off by the preparation to determine where the ligand bound most tightly. This gives them some indication of where the receptors are located. 

Snyder and Pert helped neuroscience by identifying the opioid receptor, the protein in the brain that is responsive to painkilling drugs such as morphine and opium. Their initial conclusion was that these drugs bind to the receptors, causing the change in pain sensitivity. Secondarily, they suggested that the receptors were in place because the body naturally makes chemicals that are similar to the exogenous opioid substances. 

Their major work was published in 1973 in Science. (Opiate receptor: demonstration in nervous tissue.)

Snyder won the Albert Lasker Award for Basic Medical Research in 1978 for his work characterizing the opioid receptor and the endogenous opioid chemicals that our body synthesizes and uses. 

More recently, Snyder developed the theory that the gas nitric oxide can serve as a neurotransmitter. Prior to this, it was assumed that gaseous substances do not signal the nervous system the same way that other chemicals do. Snyder argued that nitric oxide signals through the soluble guanylate cyclase protein, which increases intracellular cGMP, a secondary signaling molecule. 

He also has one of the highest h-indexes among biomedical researchers, a remarkable 275 as of 2019.