title: Effects of eszopiclone and zolpidem on sleep and waking states in the adult guinea pig.
abstract: OBJECTIVE
  The present study was designed to compare and contrast the effects of eszopiclone and zolpidem on the states of sleep and wakefulness in chronically instrumented, unanesthetized adult guinea pigs.
  
  
  METHODS
  Adult guinea pigs were implanted with electrodes to record sleep and waking states and to perform a frequency analysis of the EEG. Eszopiclone (1 and 3 mg/kg) and zolpidem (1 and 3 mg/kg) were administered intraperitoneally.
  
  
  RESULTS
  The administration of eszopiclone (1 and 3 mg/kg) resulted in a significant dose-dependent increase in NREM sleep. Zolpidem produced a significant increase in NREM sleep, but only at a dose of 3 mg/kg. The following changes in NREM and REM sleep, as well as in the power spectra, were all significant when the effects of 1 and 3 mg/kg of eszopiclone were compared with responses induced with 1 and 3 mg/kg of zolpidem, respectively: The increase in NREM sleep produced by eszopiclone was greater than that following the administration of zolpidem. The mean latency to NREM sleep following the administration of eszopiclone was significantly shorter than zolpidem. Eszopiclone significantly increased the latency to REM sleep. The mean duration of episodes of NREM sleep was increased by eszopiclone, but not by zolpidem. The EEG power increased in the delta band and decreased in the theta band during NREM sleep following the administration of eszopiclone. No significant changes occurred in any of the frequency bands analyzed following zolpidem administration.
  
  
  CONCLUSIONS
  The differences in the effects of eszopiclone and zolpidem on sleep and waking states and the power spectra of the EEG likely reflect the fact that eszopiclone and zolpidem bind to different subunits of the GABAA receptor complex.
authors.affiliation: WebSciences International, Los Angeles, CA, USA.
authors.forename: Mingchu
authors.initials: M
authors.lastname: Xi
authors.forename: Michael H
authors.initials: MH
authors.lastname: Chase
mesh_terms: D000818:Animals; D053961:Azabicyclo Compounds / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects; D000069582:Eszopiclone; D006168:Guinea Pigs; D007274:Injections, Intraperitoneal; D010879:Piperazines / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D011963:Receptors, GABA-A / Q000187:drug effects; D012815:Signal Processing, Computer-Assisted; D012890:Sleep / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects*; D014851:Wakefulness / Q000187:drug effects*; D000077334:Zolpidem
chemical_list: D053961:Azabicyclo Compounds; D010879:Piperazines; D011725:Pyridines; D011963:Receptors, GABA-A; D000077334:Zolpidem; D000069582:Eszopiclone