Changes in effective connectivity by propofol sedation

PLoS One. 2013 Aug 19;8(8):e71370. doi: 10.1371/journal.pone.0071370. eCollection 2013.

Abstract

Mechanisms of propofol-induced loss of consciousness remain poorly understood. Recent fMRI studies have shown decreases in functional connectivity during unconsciousness induced by this anesthetic agent. Functional connectivity does not provide information of directional changes in the dynamics observed during unconsciousness. The aim of the present study was to investigate, in healthy humans during an auditory task, the changes in effective connectivity resulting from propofol induced loss of consciousness. We used Dynamic Causal Modeling for fMRI (fMRI-DCM) to assess how causal connectivity is influenced by the anesthetic agent in the auditory system. Our results suggest that the dynamic observed in the auditory system during unconsciousness induced by propofol, can result in a mixture of two effects: a local inhibitory connectivity increase and a decrease in the effective connectivity in sensory cortices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adult
  • Anesthesia
  • Anesthesia, Intravenous
  • Anesthetics, Intravenous / administration & dosage*
  • Auditory Cortex / drug effects*
  • Auditory Cortex / physiology
  • Auditory Perception / physiology
  • Bayes Theorem
  • Brain Mapping
  • Female
  • Healthy Volunteers
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Narcotics / administration & dosage*
  • Neural Pathways / drug effects*
  • Neural Pathways / physiology
  • Propofol / administration & dosage*
  • Unconsciousness*

Substances

  • Anesthetics, Intravenous
  • Narcotics
  • Propofol

Grants and funding

This research was supported by the European Commission (European ICT Programme Projects FP7-247919 DECODER), the Belgian National Funds for Scientific Research (FNRS), the Tinnitus Prize 2011 (FNRS 9.4501.12), FEDER structural fund RADIOMED-930549, Fonds Léon Fredericq, the James McDonnell Foundation, the French Speaking Community Concerted Research Action and the University and University Hospital of Liège. The funding sources are not liable for any use that may be made of the information contained therein. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.