title: Function and dysfunction of hypocretin/orexin: an energetics point of view.
abstract: The basic elements of animal behavior that are critical to survival include energy, arousal, and motivation: Energy intake and expenditure are fundamental to all organisms for the performance of any type of function; according to the Yerkes-Dodson law, an optimal level of arousal is required for animals to perform normal functions; and motivation is critical to goal-oriented behaviors in higher animals. The brain is the primary organ that controls these elements and, through evolution, has developed specialized structures to accomplish this task. The orexin/hypocretin system in the perifornical/lateral hypothalamus, which was discovered 15 years ago, is one such specialized area. This review summarizes a fast-growing body of evidence discerning how the orexin/hypocretin system integrates internal and external cues to regulate energy intake that can then be used to generate sufficient arousal for animals to perform innate and goal-oriented behaviors.
authors.affiliation: Yale Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; email: xiao-bing.gao@yale.edu , tamas.horvath@yale.edu.
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Gao
authors.forename: Tamas
authors.initials: T
authors.lastname: Horvath
mesh_terms: D000818:Animals; D001143:Arousal / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D007026:Hypothalamic Area, Lateral / Q000502:physiology* / Q000503:physiopathology*; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D009042:Motivation / Q000502:physiology*; D009290:Narcolepsy / Q000503:physiopathology*; D009479:Neuropeptides / Q000502:physiology*; D000068797:Orexins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins
keywords: energy balance; hypocretin; hypocretin/orexin; motivational behavior; orexin; sleep/wake regulation