SLC6A3 and Parkinson disease: Abnormalities in the function of neuronal sodium-dependent monoamine transporters, such as the dopamine transporter DAT, have long been implicated in the etiology of a variety of neurodegenerative disorders including Parkinson's disease (PD).[1] However, the physiological and pathological roles of other amine transporters in brain, such as the organic cation transporter OCT2, are still unknown.