Agonist

Definition

An agonist is a substance that initiates a physiological response when combined with a receptor. In terms of neuroscience, it mimics the action of a naturally occurring substance.

Related terms

Antagonist: A substance that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist.

Partial Agonist: A drug that binds to and activates a given receptor but has only partial efficacy at the receptor relative to a full agonist.

Inverse Agonist: A substance that produces effects opposite those of particular neurotransmitters.