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Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-7292

Sydekum, E; Baltes, C; Ghosh, A; Mueggler, T; Schwab, M; Rudin, M (2009). Functional reorganization in rat somatosensory cortex assessed by fMRI: Elastic image registration based on structural landmarks in fMRI images and application to spinal cord injured rats. NeuroImage, 44(4):1345-1354.

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Abstract

The accuracy at which changes in cortical functional topology can be assessed by functional MRI (fMRI) depends on the quality of the reference coordinate system used for comparison of data sets obtained in different imaging sessions. Current procedures comprise an overlay of activation clusters on registered high-resolution anatomical images. Yet, fMRI images are frequently distorted due to susceptibility artifacts, which are prominent in rodent studies due to the small dimensions involved and high magnetic field strengths used. Therefore, a procedure for co-registration of activation maps has been developed based on anatomical landmarks defined on fMR echo planar images (EPI) themselves. Validation studies in control rats revealed that the centers of activated areas in somatosensory cortex S1, evoked through sensory forepaw stimulation fell within an area of 1x1 mm(2) in agreement with known electrophysiological coordinates. The technique was applied to detect changes in activation patterns in rats following smaller unilateral spinal cord injuries (SCI) in their cervical segments (C3/C4) 12 weeks after lesion. Despite of an almost complete behavioral recovery, fMRI responses remained altered in SCI animals with both significantly reduced fMRI signal amplitude and reduced latency to reach the peak response. Moreover, in SCI animals the activated S1 area corresponding to the contralesional forepaw was significantly enlarged and the center-of-mass for the ipsilesional paw was shifted rostrally. The mapping technique described combined with the temporal analysis of the BOLD response enabled a noninvasive quantitative characterization of cortical functional reorganization following SCI in rats.

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Brain Research Institute
04 Faculty of Medicine > Institute of Pharmacology and Toxicology
04 Faculty of Medicine > Institute of Biomedical Engineering
DDC:570 Life sciences; biology
170 Ethics
610 Medicine & health
Language:English
Date:February 2009
Deposited On:16 Dec 2008 13:59
Last Modified:07 Dec 2013 13:38
Publisher:Elsevier
ISSN:1053-8119
Publisher DOI:10.1016/j.neuroimage.2008.10.015
PubMed ID:19015037
Citations:Web of Science®. Times Cited: 16
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Scopus®. Citation Count: 18

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