This gene encodes the D1 subtype of the dopamine receptor. The D1 subtype is the most abundant dopamine receptor in the central nervous system. Specifically, it is is highest in the dorsal striatum (caudate and putamen) and ventral striatum (nucleus accumbens and olfatory tubercle). But lower levels of DRD1 mRNA expression occur in the basolateral amygdala, cerebral cortex, septum, thalamus, and hypothalamus. This G-protein-coupled receptor stimulates adenylyl cyclase and activates cyclic AMP-dependent protein kinases. D1 receptors regulate neuronal growth and development, mediate some behavioral responses, and modulate dopamine receptor D2-mediated events. Alternate transcription initiation sites result in two transcript variants of this gene. HiTSeeker D1 Dopamine Receptor Cell Line allows the measurement of the activity of ligands, such as Dopamine.