Homeostatic behaviors (such as eating, drinking and sleeping) help the animals to maintain their internal biochemical equilibrium. These behaviors are controlled by the nervous system with high precision, as they are important for the well-being of the whole organism. Revealing the neurobiology regulating the homeostatic behaviors is a critical aspect of understanding brain function as well as internal drives of behaviors, at the same time may help to develop treatment for abnormal behaviors resulting from the dysfunction of these regulations. Sleep is a complex homeostatic behavior, not only does it coordinate the periphery system with reduced hear rate and respiration, it also plays profound roles in the central nervous system, such as in memory consolidation. As a homeostatic behavior, sleep is driven by the need to reach a “sleep homeostasis”. The involvement of neural modulation of this sleep homeostasis remains to be mysterious in many aspects: how do different brain regions coordinate to give rise to synchronized rhythmic activity during sleep? How does sleep pause and reboot conscious experience? How does brain modulate periphery organs to maintain a stable sleep state? In order to answer all these and many other questions, a pre-requisite would be to understand the neural mechanism for sleep regulation.