Journal article
Direct MRI Mapping of Neuronal Activity Evoked by Electrical Stimulation of the Median Nerve at the Right Wrist
Magnetic resonance in medicine, Vol.61(5), pp.1073-1082
05/2009
DOI: 10.1002/mrm.21857
PMCID: PMC2743177
PMID: 19466755
Abstract
Magnetic source MRI (msMRI) has being developed recently for direct detections of neuronal magnetic fields to map brain activity. However, controversial results have been reported by different research groups. In this paper, more evidence was provided to demonstrate that the neuronal current signal could be detected by MRI using a rapid median nerve stimulation paradigm. The experiments were performed on six normal human participants to investigate the temporal specificity of the effect, as well as inter- and intra-subject reproducibility. Significant activation of contra-lateral primary sensory cortex (S1) was detected 80ms after stimulation onset (corresponding to the P80 evoked potential peak). The 80 ms latency S1 activation was observed over 3 independent sessions for one subject and for all 6 participants. The magnitude of the signal change was 0.2% - 0.3%. Coinciding with our expectations, no S1 activation was found when MRI data acquisitions were targeted at the N20 and P30 peaks because of mutual cancellation of magnetic fields generated by those peaks. The results demonstrated good reproducibility of S1 activations and indicated that the S1 activations most likely originated from neuronal magnetic field rather than hemodynamic response.
Details
- Title: Subtitle
- Direct MRI Mapping of Neuronal Activity Evoked by Electrical Stimulation of the Median Nerve at the Right Wrist
- Creators
- Yiqun Xue - Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52240Xiying Chen - Department of Radiology, University of Iowa, Iowa City, IA, 52240Thomas Grabowski - Department of Neurology, University of Iowa, Iowa City, IA, 52240Jinhu Xiong - Department of Radiology, University of Iowa, Iowa City, IA, 52240
- Resource Type
- Journal article
- Publication Details
- Magnetic resonance in medicine, Vol.61(5), pp.1073-1082
- DOI
- 10.1002/mrm.21857
- PMID
- 19466755
- PMCID
- PMC2743177
- ISSN
- 0740-3194
- eISSN
- 1522-2594
- Language
- English
- Date published
- 05/2009
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering
- Record Identifier
- 9984083275002771
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