Dopamine receptor D2 (DRD2) (DRD2)

The Dopamine receptor D2 (DRD2) is a pivotal G protein-coupled receptor (GPCR) that mediates the physiological effects of dopamine in the brain and periphery (UniProt P14416). It is primarily coupled to Gi/o proteins, leading to the inhibition of adenylyl cyclase and the modulation of ion channels, which collectively regulate neuronal firing and neurotransmitter release (StatPearls, Dopamine Receptors). DRD2 is highly expressed in the striatum and pituitary gland, serving as a key regulator of locomotor activity, reward-driven behavior, and endocrine function, specifically the inhibition of prolactin release (NCBI Gene ID: 1813). In pathology, DRD2 dysfunction is a cornerstone of the dopamine hypothesis of schizophrenia, and its loss in the nigrostriatal pathway is central to Parkinson's disease (PubMed, PMID: 11518478). Pharmacologically, DRD2 is the primary target for both first-generation and second-generation antipsychotics, which act as antagonists or partial agonists to stabilize dopaminergic tone (PubChem). Additionally, D2 agonists are standard therapy for hyperprolactinemia and Parkinson's symptoms, though their use is often limited by side effects such as extrapyramidal symptoms and metabolic changes (NIH, MedlinePlus). The specific mention of "gene expression" in the target name likely refers to the quantification of DRD2 mRNA levels, which serves as a biomarker for dopaminergic activity or drug response in various neuropsychiatric conditions.

Other names

D2RD2DRDopamine D2 receptorDRD2

Antagonism of postsynaptic D2 receptors in the mesolimbic pathway for antipsychotic effects; partial agonism for dopamine stabilization; agonism for Parkinson's disease and prolactin inhibition.