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Comparison of evoked cortical activity in conscious and propofol‐anesthetized rats using functional MRI
Author(s) -
Lahti Katariina M.,
Ferris Craig F.,
Li Fuhai,
Sotak Christopher H.,
King Jean A.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199902)41:2<412::aid-mrm28>3.0.co;2-3
Subject(s) - propofol , functional magnetic resonance imaging , somatosensory system , evoked activity , anesthesia , oxygenation , magnetic resonance imaging , intensity (physics) , shock (circulatory) , cortex (anatomy) , premovement neuronal activity , medicine , neuroscience , psychology , radiology , physics , quantum mechanics , stimulation
Changes in cortical activity during foot shock were assessed under conscious and propofol‐anesthetized conditions using functional magnetic resonance imaging (fMRI). Increases in signal intensity were observed in the contralateral somatosensory cortex in response to electrical shock of the hindpaw under both conditions. These increases in cortical signal ranged from 6% to 26% while awake and from 1% to 6% under propofol anesthesia. In each of the six animals studied, the largest increase in blood oxygenation level‐dependent (BOLD)‐based signal intensity was observed during consciousness. In three of six animals, propofol anesthesia depressed signal intensity by as much as 10‐fold, showing that the level of cortical activity during foot shock is dampened by anesthesia. These results indicate it would be advantageous to use fully conscious animals to maximize BOLD‐based MRI signal in certain behavioral studies using MR spectrometers with modest field strengths (1.0–2.0 T). Magn Reson Med 41:412–416, 1999. © 1999 Wiley‐Liss, Inc.