The emergence of the drug receptor theory.

Today, the concept of specific receptors for drugs and transmitters lies at the very heart of pharmacology. Less than one hundred years ago, this novel idea met with considerable resistance in the scientific community. To mark the 150th anniversary of the birth of John Newport Langley, one of the founders of the receptor concept, we highlight his most important observations, and those of Paul Ehrlich and Alfred Joseph Clark, who similarly helped to establish the receptor theory of drug action.