Dopamine D2 receptor; Dopamine D4 receptor (D2R; D4R)

The dopamine D2 and D4 receptors are members of the D2-like subfamily of dopamine receptors, which are G protein-coupled receptors widely expressed in the central nervous system[1][2][5][9]. D2 and D4 receptors inhibit adenylate cyclase activity upon activation, decreasing cAMP and modulating neuronal excitability and neurotransmission[3][9]. These receptors have critical roles in motor control, cognition, reward, motivation, and emotional regulation, and are major targets of current antipsychotic drugs for schizophrenia and other psychiatric disorders[1][2][4][6][9]. Most antipsychotic drugs act by antagonizing or partially agonizing D2 and D4 receptors, thereby modulating dopaminergic neurotransmission in key brain circuits implicated in disease[4][5][9]. D2 and D4 receptor dysfunction or genetic variants are linked to various neurological and psychiatric disorders, including schizophrenia, bipolar disorder, depression, ADHD, substance use disorders, and Parkinson’s disease[1][2][4][6][9]. Differences in D2 vs D4 receptor structure and distribution offer the possibility for more selective, and thus potentially safer and more effective, pharmacotherapies[1][2]. Note: For structured information or drug mapping, individual consideration of "Dopamine D2 receptor" and "Dopamine D4 receptor" is recommended.

Other names

D2 receptor (for Dopamine D2 receptor)D4 receptor (for Dopamine D4 receptor)DRD2 (gene symbol for D2)DRD4 (gene symbol for D4)Dopamine receptor D2Dopamine receptor D4D2-like dopamine receptor subfamily (group term, contains D2, D3, D4)

Antagonism: Most antipsychotics are antagonists or partial agonists at D2 and D4 receptors, blocking dopamine binding and downstream signaling (inhibiting overactive dopaminergic pathways). Partial agonism: Some newer antipsychotics (aripiprazole) act as partial agonists, modulating receptor activity to reduce side effects. Modulation of adenylate cyclase (inhibition). Differential pathway engagement (different clinical and cellular outcomes depending on drug and receptor subtype).