Dopamine receptor D2, Dopamine receptor D3, Dopamine receptor D4 (D2 receptor (DRD2), D3 receptor (DRD3), D4 receptor (DRD4))

The Dopamine receptor D2, Dopamine receptor D3, and Dopamine receptor D4 are members of the D2-like dopamine receptor subfamily, a subset of G protein-coupled receptors that mediate the inhibitory effects of dopamine in the central nervous system and peripheral tissues. These receptors share structural similarities, including seven transmembrane domains, and are coupled to Gi/o proteins that inhibit adenylyl cyclase, decreasing intracellular cAMP, and activate potassium channels. D2, D3, and D4 have distinct but overlapping distributions in the brain and play critical roles in the regulation of movement, cognition, motivation, endocrine activity, and emotion. They are key therapeutic targets for antipsychotic drugs and have been implicated in the pathophysiology and treatment of several neuropsychiatric and neurological disorders, most notably schizophrenia and Parkinson's disease.

Other names

D₂ receptorD₂RDRD2D₃ receptorD₃RDRD3D₄ receptorD₄RDRD4D2-like dopamine receptor family (collectively)

Antagonism: Most antipsychotics act as antagonists at D2, and often D3 and D4 receptors Partial agonism: Some atypical antipsychotics (e.g., aripiprazole) are partial agonists Agonism: Dopaminergic drugs used in Parkinson’s act as agonists Modulation of cAMP and potassium channel signaling