Functional connectivity changes with concentration of sevoflurane anesthesia

Neuroreport. 2005 Feb 28;16(3):285-8. doi: 10.1097/00001756-200502280-00017.


Low-frequency oscillations (<0.08 Hz) have been detected in functional magnetic resonance imaging studies, and appear to be synchronized between functionally related areas. The effect of anesthetic agents on cortical activity is not completely characterized. This study assessed the effect of anesthesia on the temporal relations in activity in the motor cortices. Resting-state magnetic resonance data were acquired on six volunteers under different anesthetic states (using 0.0%, 2.0% and 1.0% stable end-tidal sevoflurane). Across all volunteers, the number of significant voxels (p<2.5 x 10) in the functional connectivity maps was reduced by 78% for light anesthesia and by 98% for deep anesthesia, compared with the awake state. Additionally, significant correlations in the connectivity maps were bilateral in the awake state but unilateral in the light anesthesia state.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Anesthetics, Inhalation / pharmacology*
  • Brain Mapping
  • Dose-Response Relationship, Drug
  • Functional Laterality / drug effects
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / methods
  • Male
  • Methyl Ethers / pharmacology*
  • Motor Cortex / anatomy & histology
  • Motor Cortex / drug effects*
  • Motor Cortex / physiology
  • Neural Pathways / drug effects*
  • Sevoflurane
  • Wakefulness / drug effects


  • Anesthetics, Inhalation
  • Methyl Ethers
  • Sevoflurane