Studying the Dopaminergic System with Transfected Receptors

Dopamine receptors are responsible for diverse effects within and outside the central nervous system. The five dopamine receptors that have been cloned (D_1A, D_1B also known as D₅, D₂, D₃, and D₄) belong to two major families; the D₁ like and D₂ like dopamine receptors. The D₁ like receptors are linked to the stimulation while D₂ like receptors are linked to the inhibition of adenylyl cyclase. The physiologic role of the dopamine receptors has been difficult to decipher because several of the subtypes co-exist in the same tissue. However, studies of receptors artificially expressed using transfected cDNA have revealed some of the biochemical mechanisms unique to each dopamine receptor subtype.