Brain network integration dynamics are associated with loss and recovery of consciousness induced by sevoflurane


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Authors
Ranft, Andreas 
Ilg, Rüdiger 
Jordan, Denis 
Abstract

Abstract: The dynamic interplay of integration and segregation in the brain is at the core of leading theoretical accounts of consciousness. The human brain dynamically alternates between a sub‐state where integration predominates, and a predominantly segregated sub‐state, with different roles in supporting cognition and behaviour. Here, we combine graph theory and dynamic functional connectivity to compare resting‐state functional MRI data from healthy volunteers before, during, and after loss of responsiveness induced with different concentrations of the inhalational anaesthetic, sevoflurane. We show that dynamic states characterised by high brain integration are especially vulnerable to general anaesthesia, exhibiting attenuated complexity and diminished small‐world character. Crucially, these effects are reversed upon recovery, demonstrating their association with consciousness. Higher doses of sevoflurane (3% vol and burst‐suppression) also compromise the temporal balance of integration and segregation in the human brain. Additionally, we demonstrate that reduced anticorrelations between the brain's default mode and executive control networks dynamically reconfigure depending on the brain's state of integration or segregation. Taken together, our results demonstrate that the integrated sub‐state of brain connectivity is especially vulnerable to anaesthesia, in terms of both its complexity and information capacity, whose breakdown represents a generalisable biomarker of loss of consciousness and its recovery.

Description

Funder: Canadian Institute for Advanced Research; Id: http://dx.doi.org/10.13039/100007631


Funder: Gates Cambridge Trust; Id: http://dx.doi.org/10.13039/501100005370


Funder: Queens College Cambridge


Funder: Stephen Erskine Fellowship


Funder: Royal College Of Anaesthetists; Id: http://dx.doi.org/10.13039/501100001297


Funder: British Oxygen Professorship


Funder: Technische Universität München; Id: http://dx.doi.org/10.13039/501100005713

Keywords
RESEARCH ARTICLE, RESEARCH ARTICLES, anaesthesia, complexity, consciousness, dynamic functional connectivity, integration‐segregation, sevoflurane, small‐world network
Journal Title
Human Brain Mapping
Conference Name
Journal ISSN
1065-9471
1097-0193
Volume Title
42
Publisher
John Wiley & Sons, Inc.
Sponsorship
Medical Research Council (MR/M009041/1)
National Institute for Health Research (Cambridge Biomedical Research Centre, Senior Investigator Award)