This application seeks core support from the Mental Retardation/Developmental Disabilities Branch of the National Institute of Child Health and Human Development for the Wisconsin Mental Retardation Developmental Disabilities Research Center (MRDDRC). The Wisconsin MRDDRC, at the Waisman Center of the University of Wisconsin-Madison, is the focal point for the University of Wisconsin in the development of new knowledge about mental retardation and related developmental disabilities. The application seeks support for an Administrative Core and four research Cores: Research Participation;Brain Imaging;Cellular and Molecular Neuroscience;and Rodent Models. These Cores provide essential, high-quality and unique services at costs that are below the rates of those services if purchased from outside the MRDDRC. This application proposes to provide Core support for 76 research projects to be conducted by 51 investigators in three research groups pursuing biomedical and behavioral research. The three research groups are: Molecular and Genetics Sciences Group (MGSG), Communication and Cognitive Processes Group (CCPG), and Social and Affective Processes Group (SAPG). This research is designed to provide new information about the causes, consequences, and treatments/interventions for disorders that cause mental retardation and other forms of developmental disabilities. Of the 76 projects, 68 are supported by grants from the NIH, and 8 are supported by non-NIH grants.