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

Dopamine receptor D2 and dopamine receptor D3 are closely related members of the D2-like dopamine receptor subfamily. Both are **G protein-coupled receptors (GPCRs)**, which transmit signals from extracellular dopamine to intracellular pathways primarily via coupling to **Gi/o proteins**, thereby inhibiting adenylyl cyclase and reducing cAMP levels[1][2][3][4][5][6]. The **D2 receptor** exists in two isoforms—D2 short (presynaptic, autoreceptor) and D2 long (postsynaptic)[3]. The **D3 receptor** is structurally similar to D2 and is predominantly found in limbic regions, implicated in emotional and cognitive functions[3][6]. D2 and D3 receptors play key roles in the regulation of movement, mood, and reward signaling, and are major therapeutic targets in **schizophrenia, Parkinson's disease, and other neuropsychiatric disorders**[6]. Numerous antipsychotic drugs exert their effects by antagonizing these receptors, while dopamine agonists targeting D2/D3 are used to treat Parkinson’s disease and restless legs syndrome[2][4][6]. Safety concerns primarily relate to movement disorders, hormonal changes, and impulse control problems, reflecting their central role in dopaminergic neurotransmission[6].

Other names

D2 receptorD3 receptorDRD2 (gene for D2 receptor)DRD3 (gene for D3 receptor)

Antipsychotics: antagonism at D2 and/or D3 receptors, reducing dopaminergic signaling Dopamine agonists: stimulate D2 or D3 receptor, increasing dopamine-like activity Partial agonists (e.g., aripiprazole): modulate activity depending on synaptic dopamine levels