The purpose of this project is to increase and improve aging research on nonhuman primates. A Primate Colony for Aging Research will be established for: (1) longitudinal, multidisciplinary study of the biology of aging in the pigtail macaque (Macaca nemestrina) as a nonhuman primate model of human aging processes and (2) to study the influence of aging of the primate central nervous system on vulnerability to toxic effects of psychotherapeutic drugs commonly used in clinical geriatrics. The initial colony will consist of 64 animals equally divided into four age groups representing young, mature, middle-aged, and old adults. Access to the animals, provision of blood samples and innocuous biopsy specimens will be accorded to collaborating investigators for studies on basic mechanisms relating to the immunosenescene, atherosclerosis, diabetes, osteoporosis, vulnerability to stress, cognitive behavior, social behavior, and the genetic control of longevity in the primate. At the end of the longitudinal studies half of the animals in each age group will be sacrificed and specimens distributed to a larger number of investigators for studies related to those and other problems of humans aging. Priority in the provision will go to studies that are likely to elucidate findings from the premortem studies, investigations that must be carried out on primates if the results are to have relevance to human aging, and studies to determine in what respects species genetically more distant from man, but more plentiful and less expensive than primates, can serve as adequate models for problems of human aging. The cost-effectiveness of the colony as a research resource will be maximized by use of the same animals for multiple, scientifically compatible studies and by establishing a central computerized date base to allow investigators studying related aspects of aging and disease to integrate their findings.