SLC6A3 and Parkinson disease: MPTP (1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine) has long been used to generate animal models of PD that have proved instrumental in advancing both our knowledge and therapeutic approach to the treatment of PD.53,54 Following systemic dosing, MPTP crosses the blood-brain-barrier and, after conversion into 1-methyl-4-phenylpyridinium (MPP+) by astrocyte-derived monoamine oxidase, is taken up via dopamine transporters (DAT) into dopaminergic neurons.