Recent progress in orexin/hypocretin physiology and pharmacology.

Abstract Orexin peptides and their cognate receptors were discovered 14 years ago. They soon took a very central position in the regulation of sleep and wakefulness. Active studies have further elucidated these functions as well as the role of orexins in, for instance, appetite, metabolism, analgesia, addiction, and stress response. This review summarizes all the important fields but especially aims at focusing on novel findings and future directions.