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 presyn-aptic Gq-coupled receptors, either hM3Dq or mGlu5, drove rapid biphasic DAT membrane trafficking in ex vivo striatal slices, with region-specific differences between ventral and dorsal striata. DAT insertion required D2 DA autoreceptors and intact retromer, whereas DAT retrieval required PKC activation and Rit2. Ex vivo voltammetric studies revealed that DAT trafficking impacts DA clearance. Furthermore, dopami-nergic mGlu5 silencing elevated DAT surface expression and abolished motor learning, which was rescued by inhibiting DAT with a subthreshold CE-158 dose. We discovered that presynaptic DAT trafficking is complex, multimodal, and re-gion specific, and for the first time, we identified cell autono-mous mechanisms that govern presynaptic DAT tone. Importantly, the findings are consistent with a role for regu-lated DAT trafficking in DA clearance and motor function.

Automated summary

In this study, the authors used chemogenetics and conditional gene silencing to investigate the regulation of the dopamine transporter (DAT). They found that activating presynaptic Gq-coupled receptors led to rapid changes in DAT trafficking, with different effects in ventral and dorsal striatal regions. They also identified the specific mechanisms involved in DAT insertion and retrieval. In addition, they showed that DAT trafficking affects dopamine clearance and motor learning. These findings provide important insights into the regulation of DAT and its role in dopamine signaling and behaviors.