title: Correlation between EEG rhythms during sleep: surface versus mediotemporal EEG.
abstract: We compared surface and intracranial electroencephalogram recordings of mediotemporal structures. These structures are critically involved in declarative memory formation and memory consolidation during sleep. As memory processing is suggested to involve the interplay between fast and slow oscillations, we hypothesized different correlations between frequency bands in surface versus mediotemporal electroencephalogram recordings. Polysomnographic recordings obtained in 10 patients with unilateral temporal lobe epilepsy were analyzed. In accordance with earlier studies, we observed that power density in surface electroencephalogram is organized reciprocally between delta/theta and fast frequencies above 16 Hz during non-rapid-eye-movement sleep (negative correlations). In contrast, we found that within the hippocampus delta/theta power alternated in parallel with fast oscillations above 16 Hz during non-rapid-eye-movement sleep (positive correlations).
authors.affiliation: Department of Epileptology, University of Bonn, Bonn, Germany.
authors.forename: Annkathrin
authors.initials: A
authors.lastname: Poepel
authors.forename: Christoph
authors.initials: C
authors.lastname: Helmstaedter
authors.forename: Edgar
authors.initials: E
authors.lastname: Kockelmann
authors.forename: Nikolai
authors.initials: N
authors.lastname: Axmacher
authors.forename: Wieland
authors.initials: W
authors.lastname: Burr
authors.forename: Christian E
authors.initials: CE
authors.lastname: Elger
authors.forename: Juergen
authors.initials: J
authors.lastname: Fell
mesh_terms: D000328:Adult; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D012890:Sleep / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology