title: Are spatial memories strengthened in the human hippocampus during slow wave sleep?
abstract: In rats, the firing sequences observed in hippocampal ensembles during spatial learning are replayed during subsequent sleep, suggesting a role for posttraining sleep periods in the offline processing of spatial memories. Here, using regional cerebral blood flow measurements, we show that, in humans, hippocampal areas that are activated during route learning in a virtual town are likewise activated during subsequent slow wave sleep. Most importantly, we found that the amount of hippocampal activity expressed during slow wave sleep positively correlates with the improvement of performance in route retrieval on the next day. These findings suggest that learning-dependent modulation in hippocampal activity during human sleep reflects the offline processing of recent episodic and spatial memory traces, which eventually leads to the plastic changes underlying the subsequent improvement in performance.
authors.affiliation: Cyclotron Research Center, University of Liège, B-4000 Liège, Belgium. philippe.peigneux@ulg.ac.be
authors.forename: Philippe
authors.initials: P
authors.lastname: Peigneux
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
authors.forename: Sonia
authors.initials: S
authors.lastname: Fuchs
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
authors.forename: Fabien
authors.initials: F
authors.lastname: Perrin
authors.forename: Jean
authors.initials: J
authors.lastname: Reggers
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: Guy
authors.initials: G
authors.lastname: Del Fiore
authors.forename: Joël
authors.initials: J
authors.lastname: Aerts
authors.forename: André
authors.initials: A
authors.lastname: Luxen
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D004585:Electrooculography / Q000379:methods; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D017286:Polysomnography; D049268:Positron-Emission Tomography / Q000379:methods; D012815:Signal Processing, Computer-Assisted; D012890:Sleep / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology