Heterogeneity in reagents from laboratory to laboratory is a major impediment to comparing and replicating results. This has proven to be particularly true of synthetic Abeta, primary cultures and mouse colonies. The goal of Specific Aim 1 is to provide radioactive and non-radioactive synthetic Abeta peptides of standard quality and purity to all Projects. Synthetic Abeta produced at the W. M. Keck Facility at Yale University will be purified using high-performance liquid chromatography (HPLC) and the final products characterized by analytical reverse phase HPLC, amino acid analysis, laser desorption mass spectrometry and circular dichroism spectrometry. Peptide will be labeled by iodination and [125]l-tyramine-cellobiose. Specific Aim 2 is to maintain a mouse colony that can provide genetically modified mice (young, aged, and/or pregnant) and/or tissues to the three projects located in the United States. Breeding, genotyping and aging will thereby be centralized. Mouse lines maintained by the core will include: APOE knockout, hAPOEepsilon3 and epsilon4+/+ on APOE knockout background, floxed LRP, and the neuronal- and glial- Cre-recombinase mice with which they will be crossed. Finally, core staff will teach members of all projects in standardized methods of tissue culture. The goal of the Core B is to provide standardized materials to the four projects that comprise the scientific portion of the program project. These include synthetic Abeta compound in the form(s) thought to be toxic to neurons, and genetically engineered mice that will be used to test pathways regulating production of Abeta.