title: Brain functional integration decreases during propofol-induced loss of consciousness.
abstract: Consciousness has been related to the amount of integrated information that the brain is able to generate. In this paper, we tested the hypothesis that the loss of consciousness caused by propofol anesthesia is associated with a significant reduction in the capacity of the brain to integrate information. To assess the functional structure of the whole brain, functional integration and partial correlations were computed from fMRI data acquired from 18 healthy volunteers during resting wakefulness and propofol-induced deep sedation. Total integration was significantly reduced from wakefulness to deep sedation in the whole brain as well as within and between its constituent networks (or systems). Integration was systematically reduced within each system (i.e., brain or networks), as well as between networks. However, the ventral attentional network maintained interactions with most other networks during deep sedation. Partial correlations further suggested that functional connectivity was particularly affected between parietal areas and frontal or temporal regions during deep sedation. Our findings suggest that the breakdown in brain integration is the neural correlate of the loss of consciousness induced by propofol. They stress the important role played by parietal and frontal areas in the generation of consciousness.
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium. Electronic address: jschrouff@doct.ulg.ac.be.
authors.forename: Jessica
authors.initials: J
authors.lastname: Schrouff
authors.affiliation: Inserm and UPMC Univ Paris 06, UMR-S 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Perlbarg
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Boly
authors.affiliation: Inserm and UPMC Univ Paris 06, UMR-S 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Marrelec
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Boveroux
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Audrey
authors.initials: A
authors.lastname: Vanhaudenhuyse
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Marie-Aurélie
authors.initials: MA
authors.lastname: Bruno
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.affiliation: Inserm and UPMC Univ Paris 06, UMR-S 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Pélégrini-Issac
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
authors.affiliation: Inserm and UPMC Univ Paris 06, UMR-S 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France.
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects*; D003243:Consciousness / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000187:drug effects*; D015742:Propofol / Q000494:pharmacology*; D014474:Unconsciousness / Q000139:chemically induced*; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol