Motor cortex excitability is not differentially modulated following skill and strength training. (1st October 2015)

• Record Type: Journal Article
• Authors: Leung, M.; Rantalainen, T.; Teo, W.-P.; Kidgell, D.
• Is Part Of: Neuroscience. Volume 305(2015)
• Page Start: 99
• Page End: 108
• Publication Date: 2015-10-01
• Subjects: AMT active motor threshold -- cM1 contralateral motor cortex -- CS conditioned stimulation -- CSE corticospinal excitability -- EMG electromyography -- iM1 ipsilateral M1 -- M1 primary motor cortex -- MEPs motor-evoked potentials -- MPST metronome-paced strength training -- MVC maximal voluntary isometric contraction force -- rmsEMG root mean squared EMG -- SICI short-latency intra-cortical inhibition -- SPST self-paced strength training -- TMS transcranial magnetic stimulation -- TS test stimulation; corticospinal excitability -- short-latency intra-cortical inhibition -- cross-transfer -- visuomotor skill -- metronome-paced strength -- cross education; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2015.08.007
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Skill training and strength training are associated with the same neuroplastic changes in the central nervous system. Strength training externally paced increases corticospinal excitability compared to self-paced strength training. These findings have theoretical implications for rehabilitation when prescribing motor skill training. Abstract: Aim: A single session of skill or strength training can modulate the primary motor cortex (M1), which manifests as increased corticospinal excitability (CSE) and decreased short-latency intra-cortical inhibition (SICI). We tested the hypothesis that both skill and strength training can propagate the neural mechanisms mediating cross-transfer and modulate the ipsilateral M1 (iM1). Methods: Transcranial magnetic stimulation (TMS) measured baseline CSE and SICI in the contralateral motor cortex (cM1) and iM1. Participants completed 4 sets of unilateral training with their dominant arm, either visuomotor tracking, metronome-paced strength training (MPST), self-paced strength training (SPST) or control. Immediately post training, TMS was repeated in both M1s. Results: Motor-evoked potentials (MEPs) increased and inhibition was reduced for skill and MPST training from baseline in both M1s. Self-paced strength training and control did not produce changes in CSE and SICI when compared to baseline in both M1s. After training, skill and MPST increased CSE and decreased SICI in cM1 compared to SPST and control. Skill and MPST training decreased SICI in iM1 compared to SPST and control post intervention; however, CSE in iM1 was not different across groups post training. Conclusion: Both skill training and MPST facilitated an increase in CSE and released SICI in iM1 and cM1 compared to baseline. Our results suggest that synchronizing to an auditory or a visual cue promotes neural adaptations within the iM1, which is thought to mediate cross transfer.