This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Balancing energy expenditure with energy intake, metabolic requirements and energy storage is critical for maintenance of body weight, for sustained responsiveness to metabolic signals such as glucose, insulin and leptin and for homeostatic regulation of many body systems. Our experiments are defining and testing the hypothesis that energy expenditure in BAT is a potential sink for the consumption of surplus energy intake to prevent excess energy storage in white adipose tissue. Defining energy afferent signaling pathways, as well as those efferent neural pathways controlling the BAT energy expenditure effector will contribute to our understanding of the regulation of body weight and of energy substrate availability and to the design of therapeutic strategies to control disturbances in body energy homeostasis that result in diseases such as obesity, diabetes and hypertension. Recent findings include the identification of distinct projections from the preoptic area to the dorsomedial hypothalamus and to the raphe pallidus, the characterization of an inhibitory influence on BAT from paraventricular hypothalamic neurons and the determination of a prominent role for spinal serotonin release in the cooling-evoked increase in BAT thermogenesis and energy expenditure.