title: Slow wave sleep induced by GABA agonist tiagabine fails to benefit memory consolidation.
abstract: OBJECTIVE
  Slow wave sleep (SWS) plays a pivotal role in consolidating memories. Tiagabine has been shown to increase SWS in favor of REM sleep without impacting subjective sleep. However, it is unknown whether this effect is paralleled by an improved sleep-dependent consolidation of memory.
  
  
  METHODS
  This double-blind within-subject crossover study tested sensitivity of overnight retention of declarative neutral and emotional materials (word pairs, pictures) as well as a procedural memory task (sequence finger tapping) to oral administration of placebo or 10 mg tiagabine (at 22:30).
  
  
  METHODS
  Fourteen healthy young men aged 21.9 years (range 18-28 years).
  
  
  RESULTS
  Tiagabine significantly increased the time spent in SWS and decreased REM sleep compared to placebo. Tiagabine also enhanced slow wave activity (0.5-4.0 Hz) and density of < 1 Hz slow oscillations during NREM sleep. Fast (12-15 Hz) and slow (9-12 Hz) spindle activity, in particular that occurring phase-locked to the slow oscillation cycle, was decreased following tiagabine. Despite signs of deeper and more SWS, overnight retention of memory tested after sleep the next evening (19:30) was generally not improved after tiagabine, but on average even lower than after placebo, with this impairing effect reaching significance for procedural sequence finger tapping.
  
  
  CONCLUSIONS
  Our data show that increasing slow wave sleep with tiagabine does not improve memory consolidation. Possibly this is due to functional differences from normal slow wave sleep, i.e., the concurrent suppressive influence of tiagabine on phase-locked spindle activity.
authors.affiliation: University of Tuebingen, Institute of Medical Psychology and Behavioral Neurobiology, Tuebingen, Germany.
authors.forename: Gordon B
authors.initials: GB
authors.lastname: Feld
authors.forename: Ines
authors.initials: I
authors.lastname: Wilhelm
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.forename: Sabine
authors.initials: S
authors.lastname: Groch
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Binkofski
authors.forename: Matthias
authors.initials: M
authors.lastname: Mölle
authors.forename: Jan
authors.initials: J
authors.lastname: Born
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000187:drug effects / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography; D018755:GABA Agonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D009483:Neuropsychological Tests; D009557:Nipecotic Acids / Q000494:pharmacology*; D017286:Polysomnography; D011930:Reaction Time / Q000187:drug effects; D012890:Sleep / Q000187:drug effects*; D000078308:Tiagabine; D055815:Young Adult
chemical_list: D018755:GABA Agonists; D009557:Nipecotic Acids; D000078308:Tiagabine
keywords: GABA; SWS; memory consolidation; skill memory; sleep spindles; tiagabine