Mechanisms of dopamine transporter regulation in normal and disease states

The dopamine (DA) transporter (DAT) controls the spatial and temporal dynamics of DA neurotransmission by driving reuptake of extracellular transmitter into presynaptic neurons. Many diseases such as depression, bipolar disorder, Parkinson's disease (PD), and attention deficit hyperactivity disorder (ADHD) are associated with abnormal DA levels, implicating DAT as a factor in their etiology. Medications used to treat these disorders and many addictive drugs target DAT and enhance dopaminergic signaling by suppressing transmitter reuptake. We now understand that the transport and binding properties of DAT are regulated by complex and overlapping mechanisms that provide neurons with the ability to modulate DA clearance in response to physiological demands. These processes are controlled by endogenous signaling pathways and affected by exogenous transporter ligands, demonstrating their importance for normal neurotransmission, drug abuse, and disease treatments. Increasing evidence supports the disruption of these mechanisms in DA disorders, implicating dysregulation of transport in disease etiologies and suggesting these processes as potential points for therapeutic manipulation of DA availability.