Genetically modified mouse models have been very useful in research on neurodegenerative disorders, and the proposed program will take maximal advantage of this valuable resource. The main goal of the Animal Core is to help the project leaders of this program address their research questions conclusively with the minimal number of animals 1and experiments possible. To achieve this goal, we propose five specific aims. Aim 1: Maintain all animals in a I manner that ensures the reliable selection of experimental and control groups for timely distribution to the different projects. Rodents will be housed in specific-pathogen-free animal care facilities on the San Francisco General Hospital campus of the University of California, San Francisco, and on the La Jolla campus of the University of California at San Diego (UCSD). Receipts of mice and rats, matings, pregnancies, births, weanings, coat colors, ear markings, genotyping results, pedigrees, weights, health problems, deaths, and transfers or shipments of mice will all be recorded in a database that will be accessible to all project leaders and their coworkers via the computer networks of the Gladstone Institutes and the University of California. Aim 2: Breed the different lines of genetically modified mice and determine the genotype of the resulting offspring by PCR. Breedings will include timed matings for the generation of primary neural cell and tissue cultures, and crosses between distinct lines to generate mice with two or more genetic modifications. The core personnel have ample experience in genotyping genetically modified mice and maintaining complex animal databases. Aim 3: Receive mice from the Gladstone microinjection facility and blastocyst core and identify new transgenic founders and knockin mice by PCR and southern blot analysis. Gladstone and UCSD maintain state-of-the-art facilities for the microinjection of transgenes into one-cell mouse embryos and for gene targeting to inactivate or selectively modify endogenous mouse genes. Aim 4: Periodically analyze all lines of mice to confirm that levels and patterns of (trans)gene expression have remained stable. Cerebral levels of transgene expression will be tested by quantitative fluorogenic RT-PCR. The distribution of transgene expression will be characterized in collaboration with the Neuropathology/Imaging Core. We will also collaborate closely with the Neuropathology/Imaging Core and veterinary staff to optimize our protocols for the anesthesia and perfusion of animals and for the removal, dissection, and proper storage of neural tissues. Aim 5: Ship mice to Dr. Masliah at UCSD and to investigators at other institutions and advise them on the genotyping and husbandry of the mice. We have distributed our animal models to many institutions and will continue to make our models available to the scientific community.