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Plasticity of the contralateral motor cortex following focal traumatic brain injury in the rat

Axelson, Hans W; Winkler, Tomas; Flygt, Johanna; Djupsjö, Anders; Hånell, Anders and Marklund, Niklas LU (2013) In Restorative Neurology and Neuroscience 31(1). p.73-85
Abstract

PURPOSE: Recovery is limited following traumatic brain injury (TBI) since injured axons regenerate poorly and replacement of lost cells is minimal. Behavioral improvements could instead be due to plasticity of uninjured brain regions. We hypothesized that plasticity of the uninjured hemisphere occurs contralateral to a focal TBI in the adult rat. Thus, we performed cortical mapping of the cortex contralateral to the TBI using intracortical microstimulation (ICMS).

METHODS: A focal TBI was induced using the weight-drop technique (n = 5) and sham-injured animals were used as controls (n = 4). At five weeks post-injury, ICMS was used to map the motor area contralateral to the injury. Motor responses were detected by visual inspection... (More)

PURPOSE: Recovery is limited following traumatic brain injury (TBI) since injured axons regenerate poorly and replacement of lost cells is minimal. Behavioral improvements could instead be due to plasticity of uninjured brain regions. We hypothesized that plasticity of the uninjured hemisphere occurs contralateral to a focal TBI in the adult rat. Thus, we performed cortical mapping of the cortex contralateral to the TBI using intracortical microstimulation (ICMS).

METHODS: A focal TBI was induced using the weight-drop technique (n = 5) and sham-injured animals were used as controls (n = 4). At five weeks post-injury, ICMS was used to map the motor area contralateral to the injury. Motor responses were detected by visual inspection and electromyography (EMG).

RESULTS: In sham- and brain-injured animals, numerous fore- and hindlimb motor responses contralateral to the stimulation (ipsilateral to the injury) were obtained. Compared to sham-injured controls, there was a markedly increased (p < 0.05) number of fore- and hindlimb responses ipsilateral to the stimulation after TBI.

CONCLUSION: Following focal TBI in the rat, our data suggest reorganization of cortical and/or subcortical regions in the uninjured hemisphere contralateral to a focal TBI leading to an altered responsiveness to ICMS. Although we cannot exclude that these changes are maladaptive, it is plausible that this plasticity process positively influences motor recovery after TBI.

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author
publishing date
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Contribution to journal
publication status
published
keywords
Animals, Brain Injuries, Brain Mapping, Electric Stimulation, Electromyography, Evoked Potentials, Motor, Functional Laterality, Male, Motor Cortex, Neuronal Plasticity, Rats, Rats, Sprague-Dawley, Journal Article, Research Support, Non-U.S. Gov't
in
Restorative Neurology and Neuroscience
volume
31
issue
1
pages
73 - 85
publisher
IOS Press
external identifiers
  • scopus:84873666947
ISSN
1878-3627
DOI
10.3233/RNN-2012-120242
language
English
LU publication?
no
id
1c375e89-fd2d-4f1a-8543-6bdca3d4ee79
date added to LUP
2016-12-12 15:46:27
date last changed
2018-01-07 11:40:44
@article{1c375e89-fd2d-4f1a-8543-6bdca3d4ee79,
  abstract     = {<p>PURPOSE: Recovery is limited following traumatic brain injury (TBI) since injured axons regenerate poorly and replacement of lost cells is minimal. Behavioral improvements could instead be due to plasticity of uninjured brain regions. We hypothesized that plasticity of the uninjured hemisphere occurs contralateral to a focal TBI in the adult rat. Thus, we performed cortical mapping of the cortex contralateral to the TBI using intracortical microstimulation (ICMS).</p><p>METHODS: A focal TBI was induced using the weight-drop technique (n = 5) and sham-injured animals were used as controls (n = 4). At five weeks post-injury, ICMS was used to map the motor area contralateral to the injury. Motor responses were detected by visual inspection and electromyography (EMG).</p><p>RESULTS: In sham- and brain-injured animals, numerous fore- and hindlimb motor responses contralateral to the stimulation (ipsilateral to the injury) were obtained. Compared to sham-injured controls, there was a markedly increased (p &lt; 0.05) number of fore- and hindlimb responses ipsilateral to the stimulation after TBI.</p><p>CONCLUSION: Following focal TBI in the rat, our data suggest reorganization of cortical and/or subcortical regions in the uninjured hemisphere contralateral to a focal TBI leading to an altered responsiveness to ICMS. Although we cannot exclude that these changes are maladaptive, it is plausible that this plasticity process positively influences motor recovery after TBI.</p>},
  author       = {Axelson, Hans W and Winkler, Tomas and Flygt, Johanna and Djupsjö, Anders and Hånell, Anders and Marklund, Niklas},
  issn         = {1878-3627},
  keyword      = {Animals,Brain Injuries,Brain Mapping,Electric Stimulation,Electromyography,Evoked Potentials, Motor,Functional Laterality,Male,Motor Cortex,Neuronal Plasticity,Rats,Rats, Sprague-Dawley,Journal Article,Research Support, Non-U.S. Gov't},
  language     = {eng},
  number       = {1},
  pages        = {73--85},
  publisher    = {IOS Press},
  series       = {Restorative Neurology and Neuroscience},
  title        = {Plasticity of the contralateral motor cortex following focal traumatic brain injury in the rat},
  url          = {http://dx.doi.org/10.3233/RNN-2012-120242},
  volume       = {31},
  year         = {2013},
}