In this study, we aim to create a novel approach to understanding the complexity of alpha-synuclein (a-Syn) induced pathological changes at the cellular level in the ReNVM neural progenitor cells, that can readily differentiate into dopaminergic neurons. Additionally, we aim to analyze in greater detail intracellular changes and differences in extracellular signaling induced by a-Syn in a dosage-dependent manner.We created novel neuronal cell models of PD in ReNVM cells background, stably overexpressing GFP-tagged a-Syn either wild type (WT) or its A53T mutant via lentivirus transduction. Cells were then sorted into three sub-populations based on GFP expression and analyzed for a-Syn levels and intracellular distribution comparing sub-populations among themselves, between WT and A53T and with cells not overexpressing a-Syn. We then qualitatively profiled various species of a-Syn including its phosphorylated or aggregated forms along with investigating the effects on cell viability, and mitochondrial morphology and function. Excitingly, we started investigating the intercellular spreading of a-Syn-related signaling through extracellular vesicles (EVs) isolated from these cell models.We successfully characterized novel cellular models for the investigation of the role of a-Syn. Our study revealed differences in cellular responses based on a-Syn levels, along with a comparative investigation of the effects of WT and A53T a-Syn overexpression. Moreover, we analyzed the differences in the spreading of pathological a-Syn signals mediated by EVs depending on the a-Syn level.Findings from this study clarify the complex cellular processes that underlie a-Syn-related pathologies in PD.This study was supported by: APVV-20-0331, SASPRO 2_1085/01/02, ICGEB CRP/SVK22-04_EC.