Dopamine receptor D2, Dopamine receptor D3 (D2R, D3R)

Dopamine receptor D2 and D3 are closely related subtypes of the dopamine receptor family, both belonging to the G protein-coupled receptor (GPCR) superfamily. They are mainly coupled to Gi/o proteins and inhibit adenylyl cyclase, thereby modulating neuronal excitability and neurotransmitter release. D2 and D3 receptors are widely expressed in the central nervous system. D2 receptors are pivotal for the action of most antipsychotic drugs and are present as both postsynaptic (regulating neuronal activity) and presynaptic autoreceptors (modulating dopamine release), with distinct isoforms. D3 receptors, while similar in structure, have a more restricted distribution and are implicated in cognition, emotional regulation, and reward pathways. Both receptors are fundamental in the pathophysiology and treatment of psychiatric and movement disorders, but their modulation can give rise to significant clinical side effects and therapeutic challenges.

Other names

D2 receptorD2RD3 receptorD3RDRD2 (gene for D2 receptor)DRD3 (gene for D3 receptor)

Antipsychotics act as D2 (and often D3) receptor antagonists, blocking dopamine signaling and reducing positive symptoms of schizophrenia and other psychoses. Dopamine agonists stimulate D2/D3 receptors to substitute for lost dopaminergic signaling in Parkinson’s disease.