title: Propagated infra-slow intrinsic brain activity reorganizes across wake and slow wave sleep.
abstract: Propagation of slow intrinsic brain activity has been widely observed in electrophysiogical studies of slow wave sleep (SWS). However, in human resting state fMRI (rs-fMRI), intrinsic activity has been understood predominantly in terms of zero-lag temporal synchrony (functional connectivity) within systems known as resting state networks (RSNs). Prior rs-fMRI studies have found that RSNs are generally preserved across wake and sleep. Here, we use a recently developed analysis technique to study propagation of infra-slow intrinsic blood oxygen level dependent (BOLD) signals in normal adults during wake and SWS. This analysis reveals marked changes in propagation patterns in SWS vs. wake. Broadly, ordered propagation is preserved within traditionally defined RSNs but lost between RSNs. Additionally, propagation between cerebral cortex and subcortical structures reverses directions, and intra-cortical propagation becomes reorganized, especially in visual and sensorimotor cortices. These findings show that propagated rs-fMRI activity informs theoretical accounts of the neural functions of sleep.
authors.affiliation: Department of Radiology, Washington University in St. Louis, St. Louis, United States.
authors.forename: Anish
authors.initials: A
authors.lastname: Mitra
authors.affiliation: Department of Radiology, Washington University in St. Louis, St. Louis, United States.|Department of Neurology, Washington University in St. Louis, St. Louis, United States.
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Snyder
authors.affiliation: Institute for Medical Psychology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.|Department of Neurology, Brain Imaging Center, Goethe-Universität Frankfurt am Main, Frankfurt, Germany.
authors.forename: Enzo
authors.initials: E
authors.lastname: Tagliazucchi
authors.affiliation: Department of Neurology, Brain Imaging Center, Goethe-Universität Frankfurt am Main, Frankfurt, Germany.|Department of Neurology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Laufs
authors.affiliation: Department of Radiology, Washington University in St. Louis, St. Louis, United States.|Department of Neurology, Washington University in St. Louis, St. Louis, United States.
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Raichle
mesh_terms: D001921:Brain / Q000502:physiology*; D058256:Brain Waves; D004569:Electroencephalography; D006801:Humans; D008279:Magnetic Resonance Imaging; D012890:Sleep; D014851:Wakefulness
keywords: consciousness; dynamics; fMRI; human; human biology; medicine; neuroscience; propagation; resting state; slow wave sleep