title: Large-scale cortical dynamics of sleep slow waves.
abstract: Slow waves constitute the main signature of sleep in the electroencephalogram (EEG). They reflect alternating periods of neuronal hyperpolarization and depolarization in cortical networks. While recent findings have demonstrated their functional role in shaping and strengthening neuronal networks, a large-scale characterization of these two processes remains elusive in the human brain. In this study, by using simultaneous scalp EEG and intracranial recordings in 10 epileptic subjects, we examined the dynamics of hyperpolarization and depolarization waves over a large extent of the human cortex. We report that both hyperpolarization and depolarization processes can occur with two different characteristic time durations which are consistent across all subjects. For both hyperpolarization and depolarization waves, their average speed over the cortex was estimated to be approximately 1 m/s. Finally, we characterized their propagation pathways by studying the preferential trajectories between most involved intracranial contacts. For both waves, although single events could begin in almost all investigated sites across the entire cortex, we found that the majority of the preferential starting locations were located in frontal regions of the brain while they had a tendency to end in posterior and temporal regions.
authors.affiliation: Departament de Física Teòrica and Instituto de Física Corpuscular (IFIC), Universitat de València-Consejo Superior de Investigaciones Científicas (CSIC), Burjassot, València, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Botella-Soler
authors.forename: Mario
authors.initials: M
authors.lastname: Valderrama
authors.forename: Benoît
authors.initials: B
authors.lastname: Crépon
authors.forename: Vincent
authors.initials: V
authors.lastname: Navarro
authors.forename: Michel
authors.initials: M
authors.lastname: Le Van Quyen
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult