RT Journal Article SR Electronic T1 The Wake-Promoting Hypocretin–Orexin Neurons Are in an Intrinsic State of Membrane Depolarization JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 1557 OP 1562 DO 10.1523/JNEUROSCI.23-05-01557.2003 VO 23 IS 5 A1 Emmanuel Eggermann A1 Laurence Bayer A1 Mauro Serafin A1 Benoı̂t Saint-Mleux A1 Laurent Bernheim A1 Danièle Machard A1 Barbara E. Jones A1 Michel Mühlethaler YR 2003 UL http://www.jneurosci.org/content/23/5/1557.abstract AB Wakefulness depends on the activity of hypocretin–orexin neurons because their lesion results in narcolepsy. How these neurons maintain their activity to promote wakefulness is not known. Here, by recording for the first time from hypocretin–orexin neurons and comparing their properties with those of neurons expressing melanin-concentrating hormone, we show that hypocretin–orexin neurons are in an intrinsic state of membrane depolarization that promotes their spontaneous activity. We propose that wakefulness and associated energy expenditure thus depend on that property, which allows the hypocretin–orexin neurons to maintain a tonic excitatory influence on the central arousal and peripheral sympathetic systems.