Diagnosis of Parkinson’s disease (PD) particularly at early pre-motor stages is complicated by its non-specific symptoms. This project aims to develop a non-radioactive MRI biomarker for detection of early microstructural changes and neuronal connectivity changes in neurotoxic rotenone animal model and in transgenic mice overexpressing alpha synuclein (Thy1aSyn) model of PD. This will provide a non-invasive diagnosis of pre-motor stages of PD and will improve the possibilities of innovative drug development. Recent advances in MRI methodology, especially diffusion tensor imaging (DTI) has proved to be useful biomarker in detecting substantia nigra degeneration. Consequently, resting state fMRI became a candidate as early disease biomarker, because of early changes and disruptions observed in resting state networks (RSNs) connectivity. Therefore, in this study rotenone treated and Thy1aSyn mice will be examined using DTI/fMRI imaging to evaluate the extent of nigrostriatal damage and patterns of RSNs changes before and following the development of PD-like pathology.