title: Electroencephalographic spectral and coherence analysis of ketamine in rats: correlation with behavioral effects and pharmacokinetics.
abstract: OBJECTIVE
  This study was designed to evaluate the changes in EEG power spectra and EEG coherence in a ketamine model of psychosis in rats. Analyses of behavioral measurements--locomotion and sensorimotor gating--and the pharmacokinetics of ketamine and norketamine were also conducted.
  
  
  METHODS
  Ketamine and norketamine levels in rat sera and brains were analyzed by gas chromatography-mass spectrometry after ketamine 30 mg/kg (i.p.). Ketamine 9 and 30 mg/kg (i.p.) were used in the behavioral and EEG experiments. Locomotor effects in an open field test and deficits in prepulse inhibition of acoustic startle reaction (PPI ASR) were evaluated in the behavioral experiments. EEG signals were simultaneously recorded from 12 implanted active electrodes; subsequently, an EEG power spectral and coherence analysis was performed.
  
  
  RESULTS
  Ketamine had a rapid penetration into the brain; the peak concentrations of the drug were reached within 15 min after administration. Ketamine induced marked hyperlocomotion and deficits in the PPI ASR. EEG spectral analysis mainly showed increases in EEG power as well as coherence. These were most robust at 10-15 min after the administration and influenced all parts of the spectrum with ketamine 30 mg/kg.
  
  
  CONCLUSIONS
  Ketamine at behaviorally active doses induces a robust increase in EEG power spectra and coherence. The maximum levels of change correlated with the kinetics of ketamine.
authors.affiliation: Prague Psychiatric Center, Prague, Czech Republic. palenicek@pcp.lf3.cuni.cz
authors.forename: Tomáš
authors.initials: T
authors.lastname: Páleníček
authors.forename: Michaela
authors.initials: M
authors.lastname: Fujáková
authors.forename: Martin
authors.initials: M
authors.lastname: Brunovský
authors.forename: Marie
authors.initials: M
authors.lastname: Balíková
authors.forename: Jiří
authors.initials: J
authors.lastname: Horáček
authors.forename: Ingmar
authors.initials: I
authors.lastname: Gorman
authors.forename: Filip
authors.initials: F
authors.lastname: Tylš
authors.forename: Barbora
authors.initials: B
authors.lastname: Tišlerová
authors.forename: Peter
authors.initials: P
authors.lastname: Soš
authors.forename: Věra
authors.initials: V
authors.lastname: Bubeníková-Valešová
authors.forename: Cyril
authors.initials: C
authors.lastname: Höschl
authors.forename: Vladimír
authors.initials: V
authors.lastname: Krajča
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D058256:Brain Waves / Q000187:drug effects*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects*; D007649:Ketamine / Q000493:pharmacokinetics* / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D011618:Psychotic Disorders / Q000378:metabolism / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D055139:Sensory Gating / Q000187:drug effects*
chemical_list: D007649:Ketamine