Muting, not fragmentation, of functional brain networks under general anesthesia
Changes in resting-state functional connectivity (rs-FC) under general anesthesia have been widely studied with the goal of identifying neural signatures of consciousness. This work has commonly revealed an apparent fragmentation of whole-brain network structure during unconsciousness, which has bee...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-05-01
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| Series: | NeuroImage |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1053811921001075 |
| _version_ | 1819090456616632320 |
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| author | Corson N. Areshenkoff Joseph Y. Nashed R. Matthew Hutchison Melina Hutchison Ron Levy Douglas J. Cook Ravi S. Menon Stefan Everling Jason P. Gallivan |
| author_facet | Corson N. Areshenkoff Joseph Y. Nashed R. Matthew Hutchison Melina Hutchison Ron Levy Douglas J. Cook Ravi S. Menon Stefan Everling Jason P. Gallivan |
| author_sort | Corson N. Areshenkoff |
| collection | DOAJ |
| description | Changes in resting-state functional connectivity (rs-FC) under general anesthesia have been widely studied with the goal of identifying neural signatures of consciousness. This work has commonly revealed an apparent fragmentation of whole-brain network structure during unconsciousness, which has been interpreted as reflecting a break-down in connectivity and a disruption of the brain’s ability to integrate information. Here we show, by studying rs-FC under varying depths of isoflurane-induced anesthesia in nonhuman primates, that this apparent fragmentation, rather than reflecting an actual change in network structure, can be simply explained as the result of a global reduction in FC. Specifically, by comparing the actual FC data to surrogate data sets that we derived to test competing hypotheses of how FC changes as a function of dose, we found that increases in whole-brain modularity and the number of network communities – considered hallmarks of fragmentation – are artifacts of constructing FC networks by thresholding based on correlation magnitude. Taken together, our findings suggest that deepening levels of unconsciousness are instead associated with the increasingly muted expression of functional networks, an observation that constrains current interpretations as to how anesthesia-induced FC changes map onto existing neurobiological theories of consciousness. |
| first_indexed | 2024-12-21T22:24:07Z |
| format | Article |
| id | doaj.art-a76c38f0abcc430fa33ed236ed373f4b |
| institution | Directory Open Access Journal |
| issn | 1095-9572 |
| language | English |
| last_indexed | 2024-12-21T22:24:07Z |
| publishDate | 2021-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | NeuroImage |
| spelling | doaj.art-a76c38f0abcc430fa33ed236ed373f4b2022-12-21T18:48:15ZengElsevierNeuroImage1095-95722021-05-01231117830Muting, not fragmentation, of functional brain networks under general anesthesiaCorson N. Areshenkoff0Joseph Y. Nashed1R. Matthew Hutchison2Melina Hutchison3Ron Levy4Douglas J. Cook5Ravi S. Menon6Stefan Everling7Jason P. Gallivan8Corresponding author at: Centre for Neuroscience Studies, Queens University, Kingston, ON, Canada.; Centre for Neuroscience Studies, Queens University, Kingston, ON, Canada; Department of Psychology, Queens University, Kingston, ON, CanadaCentre for Neuroscience Studies, Queens University, Kingston, ON, CanadaBiogen, Cambridge, MA, USAMassachusetts Eye and Ear Infirmary, Boston, MA, USACentre for Neuroscience Studies, Queens University, Kingston, ON, Canada; Department of Surgery, Queens University, Kingston, ON, CanadaCentre for Neuroscience Studies, Queens University, Kingston, ON, Canada; Department of Surgery, Queens University, Kingston, ON, CanadaRobarts Research Institute, University of Western Ontario, London, ON, CanadaRobarts Research Institute, University of Western Ontario, London, ON, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, ON, CanadaCentre for Neuroscience Studies, Queens University, Kingston, ON, Canada; Department of Psychology, Queens University, Kingston, ON, CanadaChanges in resting-state functional connectivity (rs-FC) under general anesthesia have been widely studied with the goal of identifying neural signatures of consciousness. This work has commonly revealed an apparent fragmentation of whole-brain network structure during unconsciousness, which has been interpreted as reflecting a break-down in connectivity and a disruption of the brain’s ability to integrate information. Here we show, by studying rs-FC under varying depths of isoflurane-induced anesthesia in nonhuman primates, that this apparent fragmentation, rather than reflecting an actual change in network structure, can be simply explained as the result of a global reduction in FC. Specifically, by comparing the actual FC data to surrogate data sets that we derived to test competing hypotheses of how FC changes as a function of dose, we found that increases in whole-brain modularity and the number of network communities – considered hallmarks of fragmentation – are artifacts of constructing FC networks by thresholding based on correlation magnitude. Taken together, our findings suggest that deepening levels of unconsciousness are instead associated with the increasingly muted expression of functional networks, an observation that constrains current interpretations as to how anesthesia-induced FC changes map onto existing neurobiological theories of consciousness.http://www.sciencedirect.com/science/article/pii/S1053811921001075Brain networkFunctional connectivityConsciousnessAnesthesia |
| spellingShingle | Corson N. Areshenkoff Joseph Y. Nashed R. Matthew Hutchison Melina Hutchison Ron Levy Douglas J. Cook Ravi S. Menon Stefan Everling Jason P. Gallivan Muting, not fragmentation, of functional brain networks under general anesthesia NeuroImage Brain network Functional connectivity Consciousness Anesthesia |
| title | Muting, not fragmentation, of functional brain networks under general anesthesia |
| title_full | Muting, not fragmentation, of functional brain networks under general anesthesia |
| title_fullStr | Muting, not fragmentation, of functional brain networks under general anesthesia |
| title_full_unstemmed | Muting, not fragmentation, of functional brain networks under general anesthesia |
| title_short | Muting, not fragmentation, of functional brain networks under general anesthesia |
| title_sort | muting not fragmentation of functional brain networks under general anesthesia |
| topic | Brain network Functional connectivity Consciousness Anesthesia |
| url | http://www.sciencedirect.com/science/article/pii/S1053811921001075 |
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