Chemistry and biology of orexin signaling.

The orexins are neurohormones that, in concert with their cognate receptors, regulate a number of important physiological processes, including feeding, sleep, reward seeking and energy homeostasis. The orexin receptors have recently emerged as important drug targets. This review provides an overview of recent development in deciphering the biology of orexin signaling as well as efforts to manipulate orexin signaling pharmacologically.