Newly Published
Perioperative Medicine  |   July 2019
Propofol Anesthesia Alters Spatial and Topologic Organization of Rat Brain Metabolism
Author Notes
  • From the Department of Anesthesiology (Y.C.), the Positron Emission Tomography Center (W.B.), and the Department of Anesthesiology (J.Z.), Huashan Hospital, Fudan University, Shanghai, China; and the Laboratory for Space Environment and Physical Science, Harbin Institute of Technology, Harbin, China (X.L.).
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • Y.C., W.B., and X.L. contributed equally to this article.
    Y.C., W.B., and X.L. contributed equally to this article.×
  • Submitted for publication October 26, 2018. Accepted for publication May 1, 2019.
    Submitted for publication October 26, 2018. Accepted for publication May 1, 2019.×
  • Correspondence: Address correspondence to Dr. Zhang: Huashan Hospital, Fudan University, No. 12 Wulumuqi Middle Road, Jin’an District, Shanghai, China 200040. snapzhang@aliyun.com. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Central and Peripheral Nervous Systems / Pharmacology
Perioperative Medicine   |   July 2019
Propofol Anesthesia Alters Spatial and Topologic Organization of Rat Brain Metabolism
Anesthesiology Newly Published on July 19, 2019. doi:10.1097/ALN.0000000000002876
Anesthesiology Newly Published on July 19, 2019. doi:10.1097/ALN.0000000000002876
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Graph theory and network analysis have been applied to neuroimaging and neurophysiologic data in the anesthetized state, but there has been little formal analysis of metabolic networks.

What This Article Tells Us That Is New:

  • The brains of rodents undergoing propofol anesthesia demonstrate reduced metabolic network connectivity and efficiency. These effects might inform the mechanism of the functional disconnections and network inefficiency observed during general anesthesia in humans.

Background: Loss of consciousness during anesthesia reduces local and global rate of cerebral glucose metabolism. Despite this, the influence of gradual anesthetic-induced changes on consciousness across the entire brain metabolic network has barely been studied. The purpose of the present study was to identify specific cerebral metabolic patterns characteristic of different consciousness/anesthesia states induced by intravenous anesthetic propofol.

Methods: At various times, 20 Sprague–Dawley adult rats were intravenously administered three different dosages of propofol to induce different anesthetic states: mild sedation (20 mg · kg−1 · h−1), deep sedation (40 mg · kg−1 · h−1), and deep anesthesia (80 mg · kg−1 · h−1). Using [18F]fluorodeoxyglucose positron emission tomography brain imaging, alterations in the spatial pattern of metabolic distribution and metabolic topography were investigated by applying voxel-based spatial covariance analysis and graph-theory analysis.

Results: Evident reductions were found in baseline metabolism along with altered metabolic spatial distribution during propofol-induced anesthesia. Moreover, graph-theory analysis revealed a disruption in global and local efficiency of the metabolic brain network characterized by decreases in metabolic connectivity and energy efficiency during propofol-induced deep anesthesia (mild sedation global efficiency/local efficiency = 0.6985/0.7190, deep sedation global efficiency/local efficiency = 0.7444/0.7875, deep anesthesia global efficiency/local efficiency = 0.4498/0.6481; mild sedation vs. deep sedation, global efficiency: P = 0.356, local efficiency: P = 0.079; mild sedation vs. deep anesthesia, global efficiency: P < 0.0001, local efficiency: P < 0.0001; deep sedation vs. deep anesthesia, global efficiency: P < 0.0001, local efficiency: P < 0.0001). A strong spatial correlation was also found between cerebral metabolism and metabolic connectivity strength, which decreased significantly with deepening anesthesia level (correlation coefficients: mild sedation, r = 0.55, deep sedation, r = 0.47; deep anesthesia, r = 0.23; P < 0.0001 between the sedation and deep anesthesia groups).

Conclusions: The data revealed anesthesia-related alterations in spatial and topologic organization of metabolic brain network, as well as a close relationship between metabolic connectivity and cerebral metabolism during propofol anesthesia. These findings may provide novel insights into the metabolic mechanism of anesthetic-induced loss of consciousness.