Functional connectivity and alterations in baseline brain state in humans

Neuroimage. 2010 Jan 1;49(1):823-34. doi: 10.1016/j.neuroimage.2009.07.028. Epub 2009 Jul 22.

Abstract

This work examines the influence of changes in baseline activity on the intrinsic functional connectivity fMRI (fc-fMRI) in humans. Baseline brain activity was altered by inducing anesthesia (sevoflurane end-tidal concentration 1%) in human volunteers and fc-fMRI maps between the pre-anesthetized and anesthetized conditions were compared across different brain networks. We particularly focused on low-level sensory areas (primary somatosensory, visual, and auditory cortices), the thalamus, and pain (insula), memory (hippocampus) circuits, and the default mode network (DMN), the latter three to examine higher-order brain regions. The results indicate that, while fc-fMRI patterns did not significantly differ (p<0.005; 20-voxel cluster threshold) in sensory cortex and in the DMN between the pre- and anesthetized conditions, fc-fMRI in high-order cognitive regions (i.e. memory and pain circuits) was significantly altered by anesthesia. These findings provide further evidence that fc-fMRI reflects intrinsic brain properties, while also demonstrating that 0.5 MAC sevoflurane anesthesia preferentially modulates higher-order connections.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Anesthesia
  • Anesthetics, Inhalation
  • Brain / physiology*
  • Brain Mapping
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Methyl Ethers
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology*
  • Pain / physiopathology
  • Pain / psychology
  • Sevoflurane
  • Young Adult

Substances

  • Anesthetics, Inhalation
  • Methyl Ethers
  • Sevoflurane