TY - JOUR
T1 - Paired-associative stimulation can modulate muscle fatigue induced motor cortex excitability changes
AU - Milanović, S.
AU - Filipović, S. R.
AU - Blesić, S.
AU - Ilić, T. V.
AU - Dhanasekaran, S.
AU - Ljubisavljević, M.
N1 - Funding Information:
We acknowledge the support of the Ministry of Science and Technology of the Republic of Serbia project 175012. Prof. Ljubisavljevic and Mr. Dhanasekaran were partly supported by FMHS Grant NP-07-21 .
PY - 2011/9/30
Y1 - 2011/9/30
N2 - The aim of this study was to examine whether the changes of the motor cortex excitability induced by muscle fatigue could be affected by prior or subsequent intervention protocol supposed to induce opposing excitability changes. For this purpose we used paired associative stimulation (PAS) method, where peripheral nerve stimuli were associated with transcranial magnetic stimulation (TMS) of the motor cortex at a fixed interstimulus interval of 25. ms. The PAS protocol used is known to produce a long lasting, long-term potentiation (LTP) like change of cortical plasticity manifested by significant increase in motor evoked potentials (MEPs) amplitude. In this study, we confirmed significant MEP size reduction following fatigue, which had been already reported in the literature. When PAS was applied either immediately before or after muscle fatigue protocol, the excitability changes were largely occluded and MEP sizes remained close to baseline levels. However, in spite of the effects on cortical excitability, conditioning with PAS did not cause any change in target fatigue measure, the endurance point, which remained the same as when fatiguing protocol was applied alone. The present results demonstrate that fatigue-related changes in cortical excitability can be modulated by either prior or subsequent excitability promoting activity. They also suggest that muscle fatigue associated changes in motor cortical excitability probably represent non-specific activity-related plasticity, rather than a direct expression of the so-called central fatigue.
AB - The aim of this study was to examine whether the changes of the motor cortex excitability induced by muscle fatigue could be affected by prior or subsequent intervention protocol supposed to induce opposing excitability changes. For this purpose we used paired associative stimulation (PAS) method, where peripheral nerve stimuli were associated with transcranial magnetic stimulation (TMS) of the motor cortex at a fixed interstimulus interval of 25. ms. The PAS protocol used is known to produce a long lasting, long-term potentiation (LTP) like change of cortical plasticity manifested by significant increase in motor evoked potentials (MEPs) amplitude. In this study, we confirmed significant MEP size reduction following fatigue, which had been already reported in the literature. When PAS was applied either immediately before or after muscle fatigue protocol, the excitability changes were largely occluded and MEP sizes remained close to baseline levels. However, in spite of the effects on cortical excitability, conditioning with PAS did not cause any change in target fatigue measure, the endurance point, which remained the same as when fatiguing protocol was applied alone. The present results demonstrate that fatigue-related changes in cortical excitability can be modulated by either prior or subsequent excitability promoting activity. They also suggest that muscle fatigue associated changes in motor cortical excitability probably represent non-specific activity-related plasticity, rather than a direct expression of the so-called central fatigue.
KW - Brain plasticity
KW - Motor cortex
KW - Muscle fatigue
KW - Paired associative stimulation
KW - TMS
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U2 - 10.1016/j.bbr.2011.04.013
DO - 10.1016/j.bbr.2011.04.013
M3 - Article
C2 - 21515308
AN - SCOPUS:79955811347
SN - 0166-4328
VL - 223
SP - 30
EP - 35
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 1
ER -