Neuroscience 2005 Abstract
| Presentation Number: | 15.2 |
|---|---|
| Abstract Title: | Functional magnetic resonance imaging detection of cortical plasticity in the rodent brain following peripheral nerve injury. |
| Authors: |
Pelled, G.*1
; Dodd, S. J.1
; Koretsky, A. P.1
1Labratory of Functional and Molecular Imaging, National Inst. of Neurological Disorders and Stroke, Natl Institutes of Health, Bethesda, MD |
| Primary Theme and Topics |
Sensory and Motor Systems - Tactile/Somatosensory -- Thalamus and Cortex |
| Session: |
15. Tactile/Somatosensory: Thalamus and Cortex I Slide |
| Presentation Time: | Saturday, November 12, 2005 1:15 PM-1:30 PM |
| Location: | Washington Convention Center - Room 201 |
| Keywords: | CORTEX, LESION, DEAFFERENTATION, BRAIN IMAGING |
The goal of this study was to use functional imaging to examine cortical plasticity and to identify neuronal activity changes in the network level after peripheral nerve injury. High resolution functional Magnetic Resonance Imaging (fMRI) has emerged as an important tool to study brain plasticity in humans and rodents in a non-invasive manner. In order to detect cortical reorganization, we have applied the common sciatic and the saphenous (the main nerves innervating the hindlimb) nerves injury model in rats, which was previously shown to induce short- as well as long-term intra-cortical plasticity changes at the cellular and at the network level. At different time points after surgery, fMRI was performed on an 11.7T animal MRI system on sham-operated rats, on sciatic nerve cut rats, and on rats where both the sciatic and saphenous nerves were cut. Electrical stimulation of the healthy hindlimb in the sham-operated and in the sciatic nerve cut rat groups resulted in normal contra-lateral somatosensory cortical activation. However, as soon as three days following the deafferentiation procedure, stimulation of the healthy hindlimb resulted in both contra- and ipsi-lateral cortical activation in rats where both nerves were cut. In order to test whether the interhemispheric connections play a role in mediating the deprived somatosensory area reorganization, the healthy somatosensory area (ipsilateral to the lesioned hindlimb lesioned) was stereotaxically lesioned using electrical stimulation seven days after the deafferentation. Seven days after the cortical lesion fMRI was performed and no activation was found either in the contra- or in the ipsi-lateral cortex (referenced to the intact hindpaw) when stimulating the healthy hindlimb. These results suggest that after peripheral nerve injury, modifications of interhemispheric connections leads to reorganization of the deprived cortical region with increased inputs from the intact cortical region.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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