title: Arousal transitions in sleep, wakefulness, and anesthesia are characterized by an orderly sequence of cortical events.
abstract: Many aspects of brain function are influenced by modulatory processes, including arousal. The most abrupt changes in arousal occur at the wake-sleep transition and at the induction of anesthetic conditions. They are accompanied by major electrophysiological changes, including an emergence of low-frequency (sleep-like) activity and a loss of mid-frequency (wake-like) activity that has been linked to feedback processes of the brain. Nevertheless, the causal relationship between these two types of electrophysiological changes, as well as the cortical mechanisms underlying changes in arousal and consciousness, remain poorly understood. To address this, we studied spontaneous electro-cortical activity during arousal changes in macaques. During sleep and at loss of consciousness induced by propofol anesthesia, we identified a prototypical sequence of cortical events in which the loss of mid-frequency activity preceded, by seconds, the increases in low-frequency activity. Furthermore, in visual areas, an influence of mid-frequency change onto high-frequency activity was observed across visual hierarchy. These results are consistent with the notion that drops in arousal and consciousness are facilitated by a release of feedback cortical inhibition.
authors: Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA. Electronic address: liux15@ninds.nih.gov.
authors: Xiao
authors: X
authors: Liu
authors: Laboratory for Adaptive Intelligence, Brain Science Institute, RIKEN, Saitama, Japan.
authors: Toru
authors: T
authors: Yanagawa
authors: Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Eye Institute, Bethesda, MD, 20892, USA.
authors: David A
authors: DA
authors: Leopold
authors: Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors: Catie
authors: C
authors: Chang
authors: Frontal Lobe Function Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors: Hiroaki
authors: H
authors: Ishida
authors: Laboratory for Adaptive Intelligence, Brain Science Institute, RIKEN, Saitama, Japan.
authors: Naotaka
authors: N
authors: Fujii
authors: Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors: Jeff H
authors: JH
authors: Duyn
mesh_terms: D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D001143:Arousal / Q000502:physiology; D058256:Brain Waves; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D000069280:Electrocorticography; D008253:Macaca mulatta; D015742:Propofol / Q000494:pharmacology*; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol
keywords: Alpha inhibitory gating; Consciousness; Feedback process; Propofol anesthesia; Resting-state global signal; Sleep