Parkinsons disease (PD) compromises motor control due to the loss of dopaminergic neurons in the substantia nigra pars compacta. At the histopathological level, PD is characterized by the accumulation of Lewy bodies, large protein inclusions containing aggregated Î±Synuclein (Î±Syn). The progression of PD involves the spreading of Î±Syn misfolding through the brain mediated by a prion-like mechanism, where the protein is transferred between cells. Here we report that Î±Syn internalization is a dynamic process, where the protein transits through different sub-cellular compartments. Importantly, cells incorporating Î±Syn develop larger protein-like inclusions when compared to Î±Syn producing cells. We developed a new tool to monitor cell-to-cell transfer of Î±Syn in vivo using an adeno-associated viral (AAV) vector expressing Î±Syn fused to a red fluorescent protein in addition to soluble EGFP to label donor cells. Intra-nigral delivery of this reporter AAV construct allowed the visualization of Î±Syn incorporation into surrounding neurons. This work provides a new tool to study Î±Syn cell-to-cell transfer in vivo and may open new opportunities to study PD pathogenesis.