Project Summary/Abstract We plan to initiate participation in the NIH U01 Consortium for Gut-Brain Communication in Parkinson’s Disease (PD) (GBPDC) including contribution of PD patients across the spectrum of disease, with and without GI symptoms and age/sex matched healthy controls into the registry. The patients will be phenotyped with in depth Parkinson’s and GI measures including clinical symptoms and physiology. A subset of the cohort will be recruited from our specific center to participate in studies of brain gut imaging to assess meal-induced gut- brain axis and autonomic alterations in PD. Data from the overall GBPDC phenotyping cohort will be used to assess the relationship between measures of gastric function with autonomic metrics and Parkinson’s symptoms (both GI and non-GI). Another subset at our center will under detailed sleep, circadian rhythm, GI motility pattern assessments in an ambulatory setting and in an inpatient clinical research center to understand the relationship between Parkinson’s disease desynchrony of central and peripheral circadian and sleep clocks with GI dysmotility. Data from the entire registry cohort will also be analyzed to assess to the relationships between PD dysfunction and gut motility.