Dopamine receptor D1 and Dopamine receptor D5 (D1R and D5R)

Dopamine receptor D1 and Dopamine receptor D5 are closely related members of the D1-like subfamily of dopamine receptors, classified as G protein-coupled receptors (GPCRs) that primarily couple to Gαs/olf proteins to stimulate production of cyclic AMP (cAMP) via activation of adenylyl cyclase. Both receptors are expressed in the central nervous system (notably in cortex, hippocampus, and striatum) and mediate the effects of dopamine on processes such as motor control, reward, working memory, and cognitive function. They share high structural similarity but differ somewhat in expression profile and affinity for dopamine, with D5 exhibiting higher affinity and more constitutive activity than D1. Selective agonists and positive allosteric modulators for D1/D5 are being developed and tested, primarily for use in Parkinson's disease, cognitive disorders, and certain psychiatric conditions. Despite their therapeutic potential, drug development targeting these receptors has been challenged by issues related to selectivity, pharmacokinetics, and tolerability.

Other names

D1-like dopamine receptor familyD1A receptor (for D1)D1BR (for D5)DRD1DRD5

Agonists stimulate the D1/D5 receptor to activate adenylyl cyclase, leading to increased cAMP production through Gαs/olf coupling and downstream signaling. Positive allosteric modulators enhance endogenous dopamine signaling at D1, increasing receptor activation.