Dopamine receptor D3 and Dopamine receptor D4 (D3 receptor (DRD3), D4 receptor (DRD4))

The Dopamine receptor D3 and Dopamine receptor D4 are members of the D2-like family of G protein-coupled receptors (GPCRs) that mediate dopamine signaling, predominantly through inhibition of adenylyl cyclase via Gi/o proteins[9][4][1]. The D3 receptor (DRD3) is mainly expressed in limbic regions such as the nucleus accumbens, thalamus, and cortex, where it modulates reward, cognition, and emotional behaviors, and is a focus in addiction, depression, and schizophrenia therapeutics[2][5][3]. The D4 receptor (DRD4) is found in the frontal cortex, amygdala, and midbrain, plays roles in cognition, attention, and emotion, and is genetically polymorphic, with certain alleles associated with neuropsychiatric disorders like ADHD[9][10][3]. Both receptors are drug targets: D4 is preferentially bound by clozapine (an antipsychotic targeting schizophrenia with reduced motor side effects), and D3 is targeted by novel antagonists and partial agonists for psychosis, drug abuse, and cognitive disorders[1][2][5][4]. Their distinct tissue localization and signaling properties make them important for drug development aiming to minimize unwanted side effects while modulating dopamine-based neurotransmission.

Other names

Dopamine receptor D3DRD3Dopamine receptor D4DRD4

Antagonist (blocking receptor signaling to attenuate psychosis, depression, addiction, etc.); Partial agonist (modulating receptor function for therapeutic effect); Allosteric modulation (altering receptor activity through non-orthosteric binding); Inhibition of adenylyl cyclase and downstream second messenger signaling