Thalamus, brainstem and salience network connectivity changes during propofol-induced sedation and unconsciousness

Brain Connect. 2013;3(3):273-85. doi: 10.1089/brain.2012.0117.

Abstract

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based on independent component analysis and a classical seed-based analysis. Contrary to previous propofol research, which mainly emphasized the importance of connectivity in the default mode network (DMN) and external control network (ECN), we focused on the salience network, thalamus, and brainstem. The importance of these brain regions in brain arousal and organization merits a more detailed examination of their connectivity response to propofol. We found that the salience network disintegrated during propofol-induced unconsciousness. The thalamus decreased connectivity with the DMN, ECN, and salience network, while increasing connectivity with sensorimotor and auditory/insular cortices. Brainstem regions disconnected from the DMN with unconsciousness, while the pontine tegmental area increased connectivity with the insulae during mild sedation. These findings illustrate that loss of consciousness is associated with a wide variety of decreases and increases of both cortical and subcortical connectivity. It furthermore stresses the necessity of also examining resting state connectivity in networks representing arousal, not only those associated with awareness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthetics, Intravenous / adverse effects*
  • Brain Mapping
  • Brain Stem / blood supply
  • Brain Stem / drug effects*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Meta-Analysis as Topic
  • Nerve Net / drug effects
  • Neural Pathways / blood supply
  • Neural Pathways / drug effects*
  • Oxygen / blood
  • Propofol / adverse effects*
  • Thalamus / blood supply
  • Thalamus / drug effects*
  • Unconsciousness / chemically induced*
  • Unconsciousness / pathology
  • Wakefulness / physiology
  • Young Adult

Substances

  • Anesthetics, Intravenous
  • Oxygen
  • Propofol