Waisman Center Intellectual and Developmental Disabilities Research Center - We seek continued support of the Waisman Center Intellectual and Developmental Disabilities Research Center, a comprehensive interdisciplinary program focused on IDD spanning the biological, behavioral, and biomedical sciences. The Waisman IDDRC brings together 60 PIs from 24 academic departments from the UW-Madison’s Schools of Medicine and Public Health, Veterinary Medicine, Agriculture and Life Sciences, Letters and Science, Education, Engineering, Social Work, and Human Ecology. This application requests support for an Administrative Core (Core A), providing scientific leadership, program and faculty development, facilitation of interdisciplinary collaboration, oversight of training programs, biostatistical and bioinformatics expertise; and dissemination of knowledges and best practices; and three innovative scientific core services: Clinical Translational (Core B), providing services, resources, and training in the recruitment of human participants, clinical research coordination/navigation, clinical assessment, behavioral methods development, and production of clinical grade biotherapeutics for use in clinical trials; Brain Imaging (Core C), providing access to state-of- the-art neuroimaging instrumentation for both human and animal studies (3T MRI, PET, and microPET scanners for human, non-human primate, and rodent scanning, an fNIRS, and an EEG recording system), as well as expertise and tools for image acquisition and analysis; and IDD Models (Core D), providing resources, expertise, and technical services in cellular and molecular neuroscience, the generation and manipulation of human pluripotent stem cell (hPSC) lines from humans with IDD conditions, as well as the generation and behavioral phenotyping of mutant or genetically engineered strains of mice and rats as models of IDD conditions. In addition, we request support for a Research Project that addresses a fundamental question on the emergence of ADHD symptoms in children with ASD, using a multidisciplinary approach that combines the power of neurobehavioral, brain imaging, statistical genomics, and machine learning analyses. We propose to provide core support to 69 research projects headed by 44 PIs addressing three broad themes relevant to IDD: 1) neurodevelopment and mechanisms, 2) disorders of the nervous system, and 3) assessments and interventions. Collectively the core services and the research project of the Waisman Center IDDRC will stimulate new interdisciplinary IDD research and enhance existing IDD investigations, with a sharp focus on discovery, prevention, and treatment for IDD conditions, and improvement of the quality of life of individuals with IDD and their families.