Publications

Abstract

OBJECTIVE: Knowledge of the functional contribution to energy homeostatic control by different brain areas is limited. This study employed a systematic approach to identify brain regions specifically influenced by a positive energy balance. METHODS: The c-fos expression was mapped throughout the mouse brain after varying durations (24 hours to up to 14 days) of high-fat diet (HFD) exposure or after reversal from a 7-day HFD to a chow diet. In parallel, the metabolic and behavioral impacts of these treatments were examined. RESULTS: A HFD elicited rapid and pronounced compensatory responses which were, however, insufficient to overcome the impact of the positive energy balance. Rapid and dynamic responses of c-fos expression throughout the brain were seen over the course of HFD exposure, with some regions showing linear-like responses and some regions exhibiting biphasic responses. The switch from HFD to chow resulted in metabolic compensations mitigating the effects of the negative energy balance and a heightened preference for sweet taste. Interestingly, this diet switch led to a significant c-fos activation in the lateral hypothalamus, an area unresponsive to HFD intervention. CONCLUSIONS: Plasticity exists in the extended brain networks facilitating rapid adaptations dependent on energy availability. Knowledge of these critical control points may provide novel antiobesity treatment targets.