PROJECT SUMMARY MULTIMODAL DISEASE CHARACTERIZATION CORE The mission of the Multimodal Disease Characterization Core (MDCC) is to develop, optimize, and validate a standardized multimodal testing pipeline to conduct the longitudinal assessment of functional, behavioral, and clinical biomarkers capable of establishing healthy aging trajectories and identify divergent phenotypic changes to corroborate the early-onset (EOAD) and late-onset (LOAD) marmoset models and establish best practices and protocols. The MDCC will support the longitudinal comprehensive phenotypic characterization of the marmoset models of Alzheimer's disease (AD) developed in the Research Projects. The MDCC will optimize state-of-the-art protocols in neuroimaging, behavioral testing and cognitive assessment, and biomarkers assays to perform longitudinal evaluations from birth through the emergence of disease onset. Neuroimaging protocols will follow the ADNI-3 data acquisition and processing pipeline to obtain PET measures of amyloid, pathological tau, and glucose metabolism, MRI measures of brain structure, and measures of task-free and task-based functional MRI. The MDCC will also optimize ultrasound imaging protocols to assess arterial stiffness and blood velocity. A behavioral testing pipeline will be developed, optimized, and validated, and will be used to characterize aging phenotypes in marmosets with test-retest reliability. Finally, the MDCC will perform measurements of fluid-based blood serum and cerebrospinal fluid biomarkers, and correlate them with functional, behavioral, cognitive, and neuroimaging changes. Work in the MDCC work will lead to the characterization and validation of marmoset models of AD, which will be invaluable in translational research to elucidate the pathogenic mechanisms of AD and contribute to developing new therapeutics for AD.