? DESCRIPTION (provided by applicant): Parkinson's disease (PD) is relentlessly progressive and despite effective symptomatic therapy in the early stages of the illness most patients have substantial morbidity and disability. There is an urgent need to understand the etiology and pathogenesis of PD so that more effective symptomatic therapies and ultimately preventive therapies can be developed. Our hypothesis is that a-synuclein, parkin and LRRK2 contribute to a complex signaling network that results in the pathogenesis of Parkinson's Disease and related disorders. The center will approach this hypothesis in a multidisciplinary manner. The center represents a multi-disciplinary, mechanistic approach involving interactive, productive investigators with complementary areas of expertise who have long been committed to studies of neurodegenerative diseases. Our center will integrate diverse advanced technologies within the center to accelerate discovery. It will work collaboratively within the Udall Center Network to accelerate discovery of disease, new therapies and disease and progression biomarkers. Through the integration of the activities of the various disciplines, the interrelationships will result in a greater scientific contribution than could be achieved if each project or center investigation were pursued individually. The Johns Hopkins Udall Center will serve as a local and national resource for PD research including broad sharing of data and clinical and biospecimen resources and fostering community outreach activities. We will provide and coordinate training of young investigators in the pathogenesis and study of Parkinson's disease and Parkinson's syndromes. The Johns Hopkins Udall Center is focused on understanding the interrelationship between parkin (Project 1), the most common cause of autosomal recessive PD, ?-synuclein (Project 2), which is causal in sporadic PD and LRRK2 (Project 4), the most common cause of autosomal dominant PD and to use our discoveries to develop disease and progression markers (Project 3) and ultimately new therapies. The insights into how these three genes interact in the pathogenesis of PD and the discovery of biomarkers would not be possible without the Udall Center structure as it enables the evaluation of these major causes of PD and the ability to evaluate findings in each arm of PD to elucidate common pathways if they exist as these may provide the best opportunities for comprehensive new therapies and biomarkers. We believe that our multi-disciplinary approach has the capacity to produce unique information concerning the mechanisms of neuronal injury in animal models of PD that will lead to a better understanding of the function and the role of ?-synuclein, parkin, and LRRK2 in normal and pathophysiologic processes related to PD.