Dopamine D2-like receptor (D2-like R)

The Dopamine D2-like receptor family, comprising the D2, D3, and D4 subtypes, belongs to the G protein-coupled receptor (GPCR) superfamily and is characterized by its coupling to Gi/o proteins to inhibit adenylyl cyclase activity [StatPearls, UniProt]. These receptors are widely distributed throughout the central nervous system, particularly in the striatum, limbic system, and pituitary gland, where they regulate motor function, reward-related behavior, and hormone secretion [PubMed, Wikipedia]. In clinical medicine, D2-like receptors are pivotal therapeutic targets; for instance, the overactivation of D2 receptors in the mesolimbic pathway is a primary driver of the positive symptoms of schizophrenia [NIH, PubChem]. Conversely, a deficiency in dopaminergic stimulation of D2 receptors in the nigrostriatal pathway is a hallmark of Parkinson's disease motor symptoms [PubMed]. Pharmacological agents targeting these receptors include antipsychotics, which act as antagonists or partial agonists to dampen excessive signaling, and dopamine agonists used to treat movement disorders [StatPearls]. However, therapeutic use is often limited by significant safety concerns, including extrapyramidal side effects, hyperprolactinemia, and the potential for developing impulse control disorders [PubMed].

Other names

D2-type dopamine receptorD2-like familyD2R/D3R/D4R familyGi-coupled dopamine receptor

Drugs targeting the Dopamine D2-like receptor family primarily act as either antagonists, partial agonists, or full agonists. Antipsychotics typically block D2 receptors to reduce dopaminergic overactivity in the mesolimbic pathway, while dopamine agonists stimulate these receptors to compensate for dopamine deficiency in the nigrostriatal pathway in Parkinson's disease [StatPearls, NIH, PubMed].