Dopamine receptor (D1, D2, D3, D4, and D5) (DRD)

Dopamine receptors are a class of G protein-coupled receptors (GPCRs) that are essential for mediating the effects of the neurotransmitter dopamine in the central nervous system (UniProt, 2024). They are categorized into two distinct families: the D1-like family (comprising D1 and D5 receptors) and the D2-like family (comprising D2, D3, and D4 receptors) (StatPearls, 2023). These receptors play a pivotal role in the regulation of motor control, reward-motivated behavior, and various cognitive functions such as executive function and attention (PubMed, PMC4156299). In Parkinson's disease, the degeneration of dopaminergic neurons in the substantia nigra leads to a deficit in dopamine, resulting in the characteristic motor symptoms of the disorder (NIH, 2023). Levodopa is a metabolic precursor that crosses the blood-brain barrier and is converted into dopamine, which then acts as an agonist at these receptors to restore signaling and alleviate symptoms (PubChem, CID 6047). However, long-term treatment targeting these receptors is often associated with significant challenges, including the development of motor fluctuations and involuntary movements known as dyskinesias (Journal of Neurology, 2021).

Other names

D1A receptorD1B receptorD2 receptorD3 receptorD4 receptorD5 receptorD1-like receptorD2-like receptorDRD1DRD2DRD3DRD4DRD5

Dopamine derived from the decarboxylation of levodopa acts as a full agonist at post-synaptic D1-like and D2-like receptors in the striatum, restoring the balance of the direct and indirect pathways in the basal ganglia to facilitate movement (StatPearls, 2023).