Dopamine D2 and D3 receptors (DRD2/3)

The Dopamine D2 and D3 receptors are members of the D2-like family of G protein-coupled receptors (GPCRs), characterized by their coupling to Gi/o inhibitory G proteins and subsequent inhibition of adenylyl cyclase. These receptors play essential roles in the central nervous system, particularly in the regulation of motor control, reward-motivated behavior, and cognitive functions. D2 receptors are extensively expressed in the striatum and are the primary target for most antipsychotic medications, whereas D3 receptors are concentrated in limbic regions such as the nucleus accumbens and are linked to emotional and cognitive regulation. Dysregulation of D2 and D3 signaling is a hallmark of major neuropsychiatric conditions, including schizophrenia, Parkinson's disease, and substance use disorders. Therapeutically, antagonists and partial agonists are used to treat psychosis by dampening overactive mesolimbic dopamine, while agonists are employed to restore motor function in Parkinson's disease and restless legs syndrome. Current drug development strategies often target these receptors to achieve a balance between therapeutic efficacy and the avoidance of debilitating side effects such as extrapyramidal symptoms.

Other names

D2RD3RDRD2DRD3D2-like dopamine receptorsDopamine receptor D2Dopamine receptor D3

Drugs targeting these receptors function as antagonists, partial agonists, or full agonists to modulate dopaminergic transmission; antipsychotics typically block postsynaptic D2/3 receptors to alleviate positive symptoms of psychosis, while Parkinson's therapies utilize agonists to compensate for endogenous dopamine loss.