title: Alterations in cyclic alternating pattern associated with phase advanced sleep are differentially modulated by gaboxadol and zolpidem.
abstract: OBJECTIVE
  to evaluate cyclic alternating pattern (CAP) in a phase advance model of transient insomnia and the effects of gaboxadol and zolpidem.
  
  
  METHODS
  a randomized, double-blind, cross-over study in which habitual sleep time was advanced by 4 h.
  
  
  METHODS
  6 sleep research laboratories in US PARTICIPANTS: 55 healthy subjects (18-57 y)
  
  
  METHODS
  Gaboxadol 15 mg (GBX), zolpidem 10 mg (ZOL), and placebo (PBO).
  
  
  METHODS
  routine polysomnographic (PSG) measures, CAP, spectral power density, and self-reported sleep measures
  
  
  RESULTS
  The phase advance model of transient insomnia produced significant changes in CAP parameters. Both GBX and ZOL significantly and differentially modified CAP parameters in the direction of more stable sleep. GBX brought the CAP rate in stage 1 sleep and slow wave sleep (SWS) closer to baseline levels but did not significantly change the CAP rate in stage 2. ZOL reduced the CAP rate in stage 2 to near baseline levels, whereas the CAP rate in stage 1 and SWS was reduced substantially below baseline levels. The CAP parameter A1 index (associated with SWS and sleep continuity) showed the highest correlation with self-reported sleep quality, higher than any traditional PSG, spectral, or other self-reported measures.
  
  
  CONCLUSIONS
  disruptions in CAP produced by phase advanced sleep were significantly and differentially modulated by gaboxadol and zolpidem. The relative independence of CAP parameters from other electrophysiological measures of sleep, their high sensitivity to sleep disruption, and their strong association with subjective sleep quality suggest that CAP variables may serve as valuable endpoints in future insomnia research.
authors.affiliation: Merck Svetnik Laboratories, Biometrics Research, Rahway, NJ 07065, USA. vladimir_svetnik@merck.com
authors.forename: Vladimir
authors.initials: V
authors.lastname: Svetnik
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ferri
authors.forename: Shubhankar
authors.initials: S
authors.lastname: Ray
authors.forename: Junshui
authors.initials: J
authors.lastname: Ma
authors.forename: James K
authors.initials: JK
authors.lastname: Walsh
authors.forename: Ellen
authors.initials: E
authors.lastname: Snyder
authors.forename: Bjarke
authors.initials: B
authors.lastname: Ebert
authors.forename: Steve
authors.initials: S
authors.lastname: Deacon
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D018755:GABA Agonists / Q000494:pharmacology*; D058785:GABA-A Receptor Agonists / Q000494:pharmacology*; D006801:Humans; D007555:Isoxazoles / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000187:drug effects / Q000379:methods / Q000706:statistics & numerical data; D011725:Pyridines / Q000494:pharmacology*; D057566:Self Report; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*; D012894:Sleep Stages / Q000187:drug effects*; D055815:Young Adult; D000077334:Zolpidem
chemical_list: D018755:GABA Agonists; D058785:GABA-A Receptor Agonists; D007555:Isoxazoles; D011725:Pyridines; D000077334:Zolpidem; C015542:gaboxadol