SLC6A3 and Parkinson disease: Although the ability of I-threo to interact with both the DAT and norepinephrine transporter (NET) [22] is documented, this action should not significantly impact the motor recovery effect of this molecule as the human tg mouse model used for this study shows a significant reduction in functional DAT at presynaptic membranes as this is retained within αSyn pathological synaptic deposits [23], as occurs in the brain of PD patients [24].