D3 dopamine receptor (D3R)

The D3 dopamine receptor (D3R), encoded by the DRD3 gene, is a G protein-coupled receptor within the D2-like family. It mediates signaling primarily through inhibition of adenylyl cyclase and exhibits the highest binding affinity for dopamine among all subtypes. D3R is predominantly found in older brain regions and is implicated in a range of neurological functions including movement, cognition, reward, emotion, and social behavior. While traditionally seen as an autoreceptor inhibiting dopamine release, recent findings highlight its neurotrophic and neuroprotective roles. It also forms heteromers and interacts with other proteins. D3R is considered a significant therapeutic target for conditions like Parkinson's disease, schizophrenia, substance use disorders, and depression. Development of selective pharmacological agents remains challenging due to its structural similarity to the D2 receptor.

Other names

DRD3

D3R primarily signals through inhibitory G-proteins to inhibit adenylyl cyclase. It regulates dopamine release as an autoreceptor and influences neuronal excitability via non-canonical arrestin-dependent pathways involving voltage-gated calcium channels. Targeting D3R involves using agonists to enhance neurotrophic support, increase dopamine content, inhibit reuptake/breakdown, and reduce alpha-synuclein aggregation, or antagonists to block receptor activity, potentially weakening immune responses or enhancing social/cognitive function.