Precise tuning of metabolic and catabolic processes is required for organisms to maintain energy homeostasis in response to environmental conditions. There are many metabolic enzymes and proteins involved in these processes to achieve energy balance. However, many details about their specific functions and mechanisms are still not fully characterized, due to the lack of appropriate and efficient approaches. The aim of my project is to unravel the mechanisms how these molecules regulate energy homeostasis. By combining various biological and optical techniques, such as genetic engineering, recombinant viral vectors, fluorescent reporters, 2-photon laser imaging/uncaging, and fluorescence lifetime imaging, I seek to investigate neuronal modulation and activities related to metabolic homeostasis at the molecular level.