title: Nitric oxide production in the basal forebrain is required for recovery sleep.
abstract: Sleep homeostasis is the process by which recovery sleep is generated by prolonged wakefulness. The molecular mechanisms underlying this important phenomenon are poorly understood. Here, we assessed the role of the intercellular gaseous signaling agent NO in sleep homeostasis. We measured the concentration of nitrite and nitrate, indicative of NO production, in the basal forebrain (BF) of rats during sleep deprivation (SD), and found the level increased by 100 +/- 51%. To test whether an increase in NO production might play a causal role in recovery sleep, we administered compounds into the BF that increase or decrease concentrations of NO. Infusion of either a NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, or a NO synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), completely abolished non-rapid eye movement (NREM) recovery sleep. Infusion of a NO donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2diolate (DETA/NO), produced an increase in NREM that closely resembled NREM recovery after prolonged wakefulness. The effects of inhibition of NO synthesis and the pharmacological induction of sleep were effective only in the BF area. Indicators of energy metabolism, adenosine, lactate and pyruvate increased during prolonged wakefulness and DETA/NO infusion, whereas L-NAME infusion during SD prevented the increases. We conclude that an increase in NO production in the BF is a causal event in the induction of recovery sleep.
authors.affiliation: Department of Physiology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
authors.forename: A V
authors.initials: AV
authors.lastname: Kalinchuk
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: D
authors.initials: D
authors.lastname: Stenberg
authors.forename: P A
authors.initials: PA
authors.lastname: Rosenberg
authors.forename: T
authors.initials: T
authors.lastname: Porkka-Heiskanen
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000818:Animals; D020667:Diagonal Band of Broca / Q000187:drug effects / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D009569:Nitric Oxide / Q000096:biosynthesis*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D012892:Sleep Deprivation / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D019344:Lactic Acid; D019289:Pyruvic Acid; D019001:Nitric Oxide Synthase; D000241:Adenosine