title: High frequency activities in the human orbitofrontal cortex in sleep-wake cycle.
abstract: We recorded human orbitofrontal electrocorticogram during wakefulness and sleep in epileptic patients using subdural electrodes. During wakefulness and rapid eye movement (REM) sleep, we observed beta activity in the raw orbitofrontal signals. Power spectral analysis demonstrated beta enhancement during wakefulness and REM sleep when compared to slow wave sleep (SWS). During the phasic REM periods, the beta power was significantly lower than during the tonic REM periods. Gamma enhancement manifested itself in four out of six subjects during the phasic periods. This study is the first that has focused on electrical activity in the human orbitofrontal cortex. Although the role of the orbitofrontal cortex during sleep still remains unclear, high frequency activities give us important suggestions in elucidating the human sleep mechanism.
authors.affiliation: Department of Psychiatry, Jichi Medical School, 3311 Yakushiji, Minamikawachi-machi, Kawachi-gun, Tochigi 329-0498, Japan. masaki@danishida.com
authors.forename: Masaki
authors.initials: M
authors.lastname: Nishida
authors.forename: Sunao
authors.initials: S
authors.lastname: Uchida
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Hirai
authors.forename: Fumikazu
authors.initials: F
authors.lastname: Miwakeichi
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Maehara
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kawai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimizu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kato
mesh_terms: D000328:Adult; D001683:Biological Clocks / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D004585:Electrooculography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000379:methods; D012890:Sleep / Q000502:physiology*; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology*