Presynaptic Gq-coupled receptors drive biphasic dopamine transporter trafficking that modulates dopamine clearance and motor function

Extracellular dopamine (DA) levels are constrained by the presynaptic DA transporter (DAT), a major psychostimulant target. Despite its necessity for DA neurotransmission, DAT regulation in situ is poorly understood, and it is unknown whether regulated DAT trafficking impacts dopaminergic signaling and/or behaviors. Leveraging chemogenetics and conditional gene silencing, we found that activating presynaptic Gq-coupled receptors, either hM3Dq or mGluR5, drove rapid biphasic DAT membrane trafficking, with region-specific differences in ventral and dorsal striata. DAT insertion required DRD2 autoreceptors and intact retromer, whereas DAT retrieval required PKC activation and Rit2. Ex vivo voltammetry revealed that DAT trafficking impacts DA clearance. Importantly, dopaminergic mGluR5 silencing elevated surface DAT, which abolished motor learning and was rescued by inhibiting DAT. We found that presynaptic DAT trafficking is complex, multimodal, and region-specific, and identify cell autonomous mechanisms governing presynaptic DAT tone. Importantly, the findings suggest regulated DAT trafficking impacts both DA clearance and motor function.