Marc Reitman is Chief of the Diabetes, Endocrinology, and Obesity Branch in the intramural NIDDK, NIH. He has been at NIH since 1986, except for 9 years at Merck where he worked on discovering and developing novel drugs for the treatment of obesity and diabetes. His current research uses mice to understand the physiology of obesity, diabetes, and body temperature. One interest is in the neural regulation of metabolic rate and body temperature, focusing on the role of an orphan G protein-coupled receptor (BRS3, bombesin receptor subtype-3) in controlling these processes in the hypothalamus and preoptic area. Another goal is elucidation of the interactions between environmental temperature, body temperature, and metabolic rate in the mouse. A long-term objective is to use knowledge about mouse thermal physiology to develop conditions under which mice are a better model for humans, allowing more accurate forecasting of human obesity drug efficacy.