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Neuroimage. 2017 Feb 15;147:295-301. doi: 10.1016/j.neuroimage.2016.12.043. Epub 2016 Dec 16.

Propofol attenuates low-frequency fluctuations of resting-state fMRI BOLD signal in the anterior frontal cortex upon loss of consciousness.

Author information

1
Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, USA. Electronic address: xiliu@mcw.edu.
2
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.
3
Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.
4
Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA.
5
Department of Anesthesiology and Center for Consciousness Science, University of Michigan, Ann Arbor, USA. Electronic address: ahudetz@med.umich.edu.

Abstract

Recent studies indicate that spontaneous low-frequency fluctuations (LFFs) of resting-state functional magnetic resonance imaging (rs-fMRI) blood oxygen level-dependent (BOLD) signals are driven by the slow (<0.1Hz) modulation of ongoing neuronal activity synchronized locally and across remote brain regions. How regional LFFs of the BOLD fMRI signal are altered during anesthetic-induced alteration of consciousness is not well understood. Using rs-fMRI in 15 healthy participants, we show that during administration of propofol to achieve loss of behavioral responsiveness indexing unconsciousness, the fractional amplitude of LFF (fALFF index) was reduced in comparison to wakeful baseline in the anterior frontal regions, temporal pole, hippocampus, parahippocampal gyrus, and amygdala. Such changes were absent in large areas of the motor, parietal, and sensory cortices. During light sedation characterized by the preservation of overt responsiveness and therefore consciousness, fALFF was reduced in the subcortical areas, temporal pole, medial orbital frontal cortex, cingulate cortex, and cerebellum. Between light sedation and deep sedation, fALFF was reduced primarily in the medial and dorsolateral frontal areas. The preferential reduction of LFFs in the anterior frontal regions is consistent with frontal to sensory-motor cortical disconnection and may contribute to the suppression of consciousness during general anesthesia.

KEYWORDS:

Fractional amplitude of low-frequency fluctuation (fALFF); Loss of consciousness; Propofol sedation; Resting-state fMRI; Spontaneous neural activity

PMID:
27993673
PMCID:
PMC5303656
DOI:
10.1016/j.neuroimage.2016.12.043
[Indexed for MEDLINE]
Free PMC Article

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