(ANALYTICAL NEUROCHEMISTRY CORE (ANC): CORE D) PROJECT SUMMARY Description: The Analytical Neurochemistry Core (ANC) supports these services: (a) Quantitation of amino acids and biogenic amines; (b) Kinetic studies of flux through metabolic pathways using stable isotopes as tracers and mass spectrometry to measure isotopic enrichment; (c) Qualitative and quantitative mass spectroscopic analyses of proteins/peptides and their modifications; and (d) Bioenergetic assays of mitochondrial function. Analyses are performed: (a) In vitro; (b) In pre-clinical animal models of intellectual and developmental disabilities (IDD); and (c) In vivo, in human patients. Users have access to a broad repertoire of analytical services, as well as expert advice with regard to experimental design and data interpretation. The core emphasizes all aspects of quality control, including assurance that studies are adequately powered and properly controlled. When feasible, analyses are performed in a blinded fashion. Relevance to IDDRC Mission: The overall theme of our Center is – “Genes, Brain and Behavior”. The primary focus of the ANC is “Brain”, or the neurochemical changes which result from gene mutation and variation. These neurochemical aberrations may contribute to the behavioral anomalies that become clinical manifestations of IDD. The ANC enables users to identify and quantify changes in brain biochemistry. Such information deepens understanding of the IDD and affords development of biomarkers with which to gauge the efficacy of therapeutic interventions. Eligibility: These services are available both to approved users of the IDDRC at CHOP/UPenn and to users at other Centers in the Network.