Systematic Review: Anesthetic Protocols and Management as Confounders in Rodent Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI)-Part B: Effects of Anesthetic Agents, Doses and Timing

Steiner, A. R. and Rousseau-Blass, F. and Schroeter, A. and Hartnack, S. and Bettschart-Wolfensberger, R.

Animals (Basel) (2021) 11:

DOI: 10.3390/ani11010199

Abstract

In rodent models the use of functional magnetic resonance imaging (fMRI) under anesthesia is common. The anesthetic protocol might influence fMRI readouts either directly or via changes in physiological parameters. As long as those factors cannot be objectively quantified, the scientific validity of fMRI in rodents is impaired. In the present systematic review, literature analyzing in rats and mice the influence of anesthesia regimes and concurrent physiological functions on blood oxygen level dependent (BOLD) fMRI results was investigated. Studies from four databases that were searched were selected following pre-defined criteria. Two separate articles publish the results; the herewith presented article includes the analyses of 83 studies. Most studies found differences in BOLD fMRI readouts with different anesthesia drugs and dose rates, time points of imaging or when awake status was compared to anesthetized animals. To obtain scientifically valid, reproducible results from rodent fMRI studies, stable levels of anesthesia with agents suitable for the model under investigation as well as known and objectively quantifiable effects on readouts are, thus, mandatory. Further studies should establish dose ranges for standardized anesthetic protocols and determine time windows for imaging during which influence of anesthesia on readout is objectively quantifiable.

Citation

Steiner, A. R., Rousseau-Blass, F., Schroeter, A., Hartnack, S., & Bettschart-Wolfensberger, R. (2021). Systematic Review: Anesthetic Protocols and Management as Confounders in Rodent Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI)-Part B: Effects of Anesthetic Agents, Doses and Timing. Animals (Basel), 11(1). https://doi.org/10.3390/ani11010199 isoflurane, mouse, rat, validity, in the collection, analyses, or interpretation of data, in the writing, of the manuscript, or in the decision to publish the results., of the study, anesthesia regime, anesthetic protocol, BOLD fMRI, medetomidine, α-chloralose

Keywords

• isoflurane
• mouse
• rat
• validity
• in the collection
• analyses
• or interpretation of data
• in the writing
• of the manuscript
• or in the decision to publish the results.
• of the study
• anesthesia regime
• anesthetic protocol
• BOLD fMRI
• medetomidine
• α-chloralose