Breakdown of local information processing may underlie isoflurane anesthesia effects

  • The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source—such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)—as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy—suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling.
Metadaten
Author:Patricia Wollstadt, Kristin K. Sellers, Lucas Rudelt, Viola PriesemannORCiDGND, Axel Hutt, Flavio Fröhlich, Michael WibralORCiDGND
URN:urn:nbn:de:hebis:30:3-436887
DOI:https://doi.org/10.1371/journal.pcbi.1005511
ISSN:1553-7358
ISSN:1553-734X
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/28570661
Parent Title (English):PLoS Computational Biology
Publisher:Public Library of Science
Place of publication:San Francisco, Calif.
Contributor(s):Claus C. Hilgetag
Document Type:Article
Language:English
Date of Publication (online):2017/06/12
Date of first Publication:2017/06/01
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2017/06/12
Volume:13
Issue:(6): e1005511
Page Number:35
First Page:1
Last Page:35
Note:
Copyright: © 2017 Wollstadt et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
HeBIS-PPN:421387246
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 4.0