title: Interplay between spontaneous and induced brain activity during human non-rapid eye movement sleep.
abstract: Humans are less responsive to the surrounding environment during sleep. However, the extent to which the human brain responds to external stimuli during sleep is uncertain. We used simultaneous EEG and functional MRI to characterize brain responses to tones during wakefulness and non-rapid eye movement (NREM) sleep. Sounds during wakefulness elicited responses in the thalamus and primary auditory cortex. These responses persisted in NREM sleep, except throughout spindles, during which they became less consistent. When sounds induced a K complex, activity in the auditory cortex was enhanced and responses in distant frontal areas were elicited, similar to the stereotypical pattern associated with slow oscillations. These data show that sound processing during NREM sleep is constrained by fundamental brain oscillatory modes (slow oscillations and spindles), which result in a complex interplay between spontaneous and induced brain activity. The distortion of sensory information at the thalamic level, especially during spindles, functionally isolates the cortex from the environment and might provide unique conditions favorable for off-line memory processing.
authors: Cyclotron Research Centre, University of Liège, B-4000 Liège, Belgium. tt.dangvu@ulg.ac.be
authors: Thien Thanh
authors: TT
authors: Dang-Vu
authors: Maxime
authors: M
authors: Bonjean
authors: Manuel
authors: M
authors: Schabus
authors: Mélanie
authors: M
authors: Boly
authors: Annabelle
authors: A
authors: Darsaud
authors: Martin
authors: M
authors: Desseilles
authors: Christian
authors: C
authors: Degueldre
authors: Evelyne
authors: E
authors: Balteau
authors: Christophe
authors: C
authors: Phillips
authors: André
authors: A
authors: Luxen
authors: Terrence J
authors: TJ
authors: Sejnowski
authors: Pierre
authors: P
authors: Maquet
mesh_terms: D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D012895:Sleep, REM / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult