Dopamine receptors D3–D5 (DRD3-5)

Dopamine receptors D3, D4, and D5 are members of the G protein-coupled receptor (GPCR) superfamily that mediate the physiological actions of the neurotransmitter dopamine in the central nervous system and periphery [1.5.1, 1.5.3]. These receptors are categorized into two distinct functional families: the D2-like family (including D3 and D4), which are coupled to Gi/o proteins to inhibit adenylyl cyclase, and the D1-like family (including D5), which are coupled to Gs/olf proteins to stimulate adenylyl cyclase [1.5.1, 1.5.4]. The D3 and D4 receptors are primarily localized in limbic regions and the prefrontal cortex, playing critical roles in reward, emotion, and cognition, making them key targets for antipsychotics and treatments for addiction [1.1.1, 1.5.5]. The D5 receptor, which exhibits a higher affinity for dopamine than the D1 subtype, is involved in memory, attention, and blood pressure regulation [1.3.1, 1.3.2]. Dysregulation of these receptors is implicated in a wide range of neuropsychiatric and neurological conditions, including schizophrenia, Parkinson's disease, and ADHD [1.4.1, 1.5.2]. Pharmacological modulation includes the use of agonists for motor symptoms in Parkinson's and antagonists or partial agonists for managing psychosis and cognitive deficits [1.2.1, 1.5.3]. Safety concerns associated with targeting these receptors include extrapyramidal symptoms and impulse control disorders [1.5.5].

Other names

Dopamine receptor D3Dopamine receptor D4Dopamine receptor D5DRD3DRD4DRD5D3DRD4DRDBDRD1beta dopamine receptorD2C dopamine receptorEssential tremor 1 (ETM1)FET1

D3 and D4 receptors are Gi/o-coupled GPCRs that inhibit adenylyl cyclase, reducing cAMP levels and decreasing neuronal excitability, while D5 receptors are Gs/olf-coupled GPCRs that stimulate adenylyl cyclase, increasing cAMP levels and activating protein kinase A (PKA) to enhance signaling; drugs act as agonists, antagonists, or partial agonists to modulate these pathways.