Where does receptor collide?

In pharmacology, a receptor is the specific cellular macromolecule to which a drug, hormone, or transmitter binds to produce its effect, so that the drug's action depends on recognition at this site rather than on the drug alone. Langley's 1905 work on nicotine and curare at striated muscle inferred a ‘receptive substance’ on the cell with which these poisons combine, laying the groundwork for receptor theory. The referent is a molecular binding-and-signalling entity defined by what it recognizes and the response it triggers, a different construct from a sense organ, which merely shares the name.[1]

Unit

The binding-and-response relationship between a ligand and its target macromolecule

Recovery means

Not applicable

Measured by

Characterized by ligand binding affinity, receptor density, and the dose-response produced on activation

In sensory physiology, a receptor is a specialized cell or nerve ending that detects a particular form of environmental energy (pressure, light, chemicals, temperature) and transduces it into trains of nerve impulses. Adrian and Zotterman's 1926 recordings from single sensory endings showed that stimulus strength is encoded in the frequency of all-or-none impulses a receptor fires. The referent is a biological transducer at the body's interface with the world, measured by its sensitivity and firing, and distinct from the drug-binding macromolecule that carries the same name.[2]

Unit

The relationship between stimulus intensity and the impulse frequency a sensory ending fires

Recovery means

Not applicable

Measured by

Studied by recording impulse frequency against graded stimulus intensity, plus thresholds and adaptation rates