Project Summary/Abstract - Animal Studies Core As it has for over a decade, the fee-for-service MDRC Animal Studies Core (ASC) (previously, the Animal Phenotyping Core- APC) provides state-of-the art equipment, services, training, and consultation regarding the detailed metabolic phenotyping of mouse and rat models of metabolic disease. T o address the previously unmet needs of MDRC members , the MDRC has invested in new technology and established a host of new services over the past five years . The ASC will continue to support these technologies and services, providing access to crucial equipment, expertise and training to empower specialized studies of rodent models of diabetes and related diseases. The ASC consists of four labs: 1) The Rat Metabolic Phenotyping Lab: includes the assessment of glucose homeostasis, whole animal metabolic assessment, body composition, and other specialized metabolic assessments in rats. 2) The Optogenetics and Behavioral Phenotyping Lab: provides training and access to optogenetic equipment to examine physiologic and behavioral responses to neural circuit manipulation, as well as with equipment to measure relevant behaviors, such as homeostatic and non-homeostatic feeding, activity, reward, and other behaviors that impact and/or are regulated by metabolic parameters in rodents. 3) The Continuous Glucose Monitoring Lab: provides continuous assessment of blood glucose concentrations in conscious, unrestrained rodents by radiotelemetry. This technology minimizes the stress of handling rodents and permits a detailed analysis of glucose fluctuations within normal feeding patterns and across extended time-frames. 4) The Islet Lab: provides islet isolation from mice and rats and ex vivo studies (including perifusion) of islets and other endocrine tissues. The ASC directly supports the goals of the MDRC. The services that the ASC provide are unique and are an important means to study rodent models of diabetes and related diseases, without which crucial aspects of diabetes-related research could not be accomplished. This core provides the necessary i nfrastructure to perform advanced, standardized, metabolic phenotyping of animal models of diabetes and related disorders that arise from genetic, pharmacologic, dietary, or other perturbations. The centralized equipment and services expedites research for many MDRC investigators in a cost-effective manner and provides access to complex metabolic techniques that they may not have otherwise.