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Confounding effects of volatile anesthesia on CBV assessment in rodent forebrain following ethanol challenge
Author(s) -
Luo Feng,
Li Zhixin,
Treistman Steven N.,
Kim Young Ro,
King Jean A.,
Fox Gerard B.,
Ferris Craig F.
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21083
Subject(s) - isoflurane , anesthesia , anesthetic , cerebral blood flow , cerebral blood volume , medicine , ethanol , forebrain , chemistry , central nervous system , organic chemistry
Purpose To compare and contrast the pattern and characteristics of the cerebral blood volume (CBV) response to ethanol (EtOH) in rats under awake and anesthetized conditions. Materials and Methods Acute EtOH (0.75 g/kg) challenge–induced CBV changes were measured using a contrast‐enhanced functional MRI CBV method in 15 male Sprague Dawley rats under three experimental conditions: 1.0% to 1.2% isoflurane ( N = 5); 0.8% halothane ( N = 5); and awake with no anesthetic ( N = 5). Physiological parameters were collected from bench settings in nine rats from the above different conditions. Four parameters: 1) area under the curve (AUC%); 2) the maximum signal change (Max%); 3) EtOH absorption rate (α 2 ); and 4) EtOH elimination rate (α 1 ) were employed to compare EtOH‐induced MRI signals between the awake and anesthetized groups. Results Both awake and anesthetized animals responded with an increase in CBV to EtOH challenge. However, the presence of anesthesia promoted a significant preferential flow to subcortical areas not seen in the awake condition. Conclusion Unclear mechanisms of anesthesia add a layer of uncertainty to the already complex interpretation of EtOH's influence on neuronal activity, cellular metabolism, and hemodynamic coupling. J. Magn. Reson. Imaging 2007;26:557–563. © 2007 Wiley‐Liss, Inc.