title: Melatonin and S-20098 increase REM sleep and wake-up propensity without modifying NREM sleep homeostasis.
abstract: The pineal hormone melatonin has been implicated in the circadian regulation of sleep. In a crossover design, we investigated the effect of acute administration of 5 mg melatonin and a melatonin agonist (S-20098, 5 and 100 mg) in healthy young men when given 5 h before bedtime on sleep structure and electroencephalogram (EEG) power density. Each trial comprised a baseline, a treatment, and a posttreatment sleep episode. Relative to the placebo condition, all treatments phase advanced the core body temperature rhythm [Kräuchi, K., C. Cajochen, D. Möri, C. Hetsch, and A. Wirz-Justice. Sleep Res. 24: 526, 1995; and Kräuchi, K., C. Cajochen, D. Möri, and A. Wirz-Justice. Am. J. Physiol. 272 (Regulatory Integrative Comp. Physiol. 41): R1178-1188, 1997]. Rapid eye movement (REM) sleep was increased after both melatonin and S-20098. This increase in REM sleep was most pronounced in the first REM sleep episode. On the posttreatment night after melatonin and S-20098 administration, more wakefulness was present in the latter one-half of the sleep episode. EEG power density between 0.25 and 20 Hz during either non-REM (NREM) or REM sleep did not differ from placebo. Thus a single early evening dose of melatonin or the agonist S-20098 increases REM sleep propensity and advances sleep termination while, at the same time, the EEG in NREM sleep remains unaffected.
authors.affiliation: Psychiatric University Clinic, Basel, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Cajochen
authors.forename: K
authors.initials: K
authors.lastname: Kräuchi
authors.forename: D
authors.initials: D
authors.lastname: Möri
authors.forename: P
authors.initials: P
authors.lastname: Graw
authors.forename: A
authors.initials: A
authors.lastname: Wirz-Justice
mesh_terms: D000081:Acetamides / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D018592:Cross-Over Studies; D003624:Darkness; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006706:Homeostasis; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D008027:Light; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000819:agonists / Q000494:pharmacology*; D010919:Placebos; D011897:Random Allocation; D012044:Regression Analysis; D012894:Sleep Stages / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects*; D014851:Wakefulness / Q000187:drug effects*; D009281:Naphthalenes
chemical_list: D000081:Acetamides; D006993:Hypnotics and Sedatives; D008550:Melatonin; D010919:Placebos; C084711:agomelatine; D009281:Naphthalenes