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Spatiotemporal dynamics of low frequency fluctuations in BOLD fMRI of the rat
Author(s) -
Majeed Waqas,
Magnuson Matthew,
Keilholz Shella D.
Publication year - 2009
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.21848
Subject(s) - somatosensory system , temporal resolution , frequency analysis , low frequency , physics , resting state fmri , dynamics (music) , visual cortex , spectral analysis , nuclear magnetic resonance , visualization , spatial frequency , neuroscience , computer science , artificial intelligence , optics , acoustics , psychology , spectroscopy , quantum mechanics , astronomy
Purpose To examine spatiotemporal dynamics of low frequency fluctuations in rat cortex. Materials and Methods Gradient‐echo echo‐planar imaging images were acquired from anesthetized rats (repetition time = 100 ms). Power spectral analysis was performed to detect different frequency peaks. Functional connectivity maps were obtained for the frequency peaks of interest. The images in the filtered time‐series were displayed as a movie to study spatiotemporal patterns in the data for frequency bands of interest. Results High temporal and spectral resolution allowed separation of primary components of physiological noise and visualization of spectral details. Two low frequency peaks with distinct characteristics were observed. Selective visualization of the second low frequency peak revealed waves of activity that typically began in the secondary somatosensory cortex and propagated to the primary motor cortex. Conclusion To date, analysis of these fluctuations has focused on the detection of functional networks assuming steady state conditions. These results suggest that detailed examination of the spatiotemporal dynamics of the low frequency fluctuations may provide more insight into brain function, and add a new perspective to the analysis of resting state fMRI data. J. Magn. Reson. Imaging 2009;30:384–393. © 2009 Wiley‐Liss, Inc.