Dopamine receptors play important roles in many neurological processes, including motivation, pleasure, cognition, memory, learning, and fine motor control; as well as modulation of neuroendocrine signaling. Abnormal dopamine receptor signaling and dopaminergic nerve function occurs in several neuropsychiatric disorders. Thus, dopamine receptors are common neurologic drug targets. The D1 and D5 receptors have a high degree of structural homology and few ligands are available that can distinguish between them as yet; however there are a number of ligands that are selective for D1/5 over the other dopamine receptors. The recent development of a selective D5 antagonist has allowed the action of D1-mediated responses to be studied in the absence of a D5 component, but no selective D5 agonists are yet available. HiTSeeker D5 Dopamine Receptor Cell Line allows the measurement of the activity of ligands, such as Dopamine.