Cross-education of muscular strength is facilitated by homeostatic plasticity
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We examined the effect of priming the ipsilateral motor cortex (M1) using anodal transcranial direct current stimulation (tDCS) prior to a single bout of strength training on the cross-transfer of strength and corticospinal excitability and inhibition of the ipsilateral M1.
In a randomized double-blinded cross-over design, changes in strength and indices of corticospinal plasticity were analysed in 13 adults who were exposed to 20 min of ipsilateral anodal and sham tDCS (applied to the ipsilateral M1 to the training arm) followed by a single strength training session of the right Biceps Brachii only.
The induction of homeostatic plasticity via anodal tDCS priming, significantly increased strength of the untrained left Biceps Brachii (12%) compared to sham tDCS (2%), increased corticospinal excitability (12–33%) and cross-activation (25%) when ipsilateral anodal tDCS was applied to the right M1 prior to a single session of strength training. Interestingly, ipsilateral sham tDCS and strength training resulted in an average increase in MEP amplitude of 2–32%.
The novel findings of this study include: priming the ipsilateral M1 via anodal tDCS prior to a single bout of strength training augments the cross-transfer of strength which is manifested by an increase in corticospinal excitability and cross-activation. These findings provide insight into how priming methods that induce homeostatic plasticity may be used to enhance the cross-education phenomenon.
KeywordsCross-education Homeostatic plasticity Priming Strength training Transcranial direct current stimulation
- Anodal tDCS + ST
Anodal transcranial direct current stimulation and strength training
Maximum compound wave
Maximal voluntary isometric contraction
Primary motor cortex
Non-invasive brain stimulation
Root-mean square electromyography
- Sham tDCS + ST
Sham transcranial direct current stimulation and strength training
Short-interval intracortical inhibition
Transcranial direct current stimulation
Transcranial magnetic stimulation
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Compliance with ethical standards
Conflict of interest
None of the authors have potential conflicts of interest to be disclosed.
- Bastani A, Jaberzadeh S (2012) Does anodal transcranial direct current stimulation enhance excitability of the motor cortex and motor function in healthy individuals and subjects with stroke: A systematic review and meta-analysis. Clin Neurophysiol 123:644–657. doi: 10.1016/j.clinph.2011.08.029 CrossRefPubMedGoogle Scholar
- Fregni F, Gimenes R, Valle AC, Ferreira MJL, Rocha RR, Natalle L, Bravo R, Rigonatti SP, Freedman SD, Nitsche MA, Pascual-Leone A, Boggio PS (2006) A randomized, sham-controlled, proof of principle study of transcranial direct current stimulation for the treatment of pain in fibromyalgia. Arthritis Rheum 54:3988–3998CrossRefPubMedGoogle Scholar
- Hortobágyi T, Taylor JL, Petersen NT, Russell G, Gandevia SC (2003a) Changes in segmental and motor cortical output with contralateral muscle contractions and altered sensory inputs in humans. J Neurophysiol 90:2451–2459. doi: 10.1152/jn.01001.2002
- Hortobágyi T, Taylor JL, Petersen NT, Russell G, Gandevia SC (2003b) Changes in segmental and motor cortical output with contralateral muscle contractions and altered sensory inputs in humans. J Neurophysiol 90:2451–2459. doi: 10.1152/jn.01001.2002
- Hunter T, Sacco P, Nitsche MA, Turner DL (2009) Modulation of internal model formation during force field-induced motor learning by anodal transcranial direct current stimulation of primary motor cortex. J Physiol 587:2949–2961. doi: 10.1113/jphysiol.2009.169284 CrossRefPubMedPubMedCentralGoogle Scholar
- Kidgell DJ, Frazer AK, Rantalainen T, Ruotsalainen I, Ahtiainen J, Avela J, Howatson G (2015) Increased cross-education of muscle strength and reduced corticospinal inhibition following eccentric strength training. Neuroscience 300:566–575. doi: 10.1016/j.neuroscience.2015.05.057 CrossRefPubMedGoogle Scholar
- Kobayashi M, Pascual-Leone A Transcranial magnetic stimulation in neurology. Lancet Neurol 2:145–156 doi: 10.1016/S1474-4422(03)00321-1
- Munn J, Herbert RD, Hancock MJ, Gandevia SC (2005a) Resistance training for strength: effect of number of sets and contraction speed. Med Sci Sports Exerc 37:1622–1626Google Scholar
- Munn J, Herbert RD, Hancock MJ, Gandevia SC (2005b) Training with unilateral resistance exercise increases contralateral strength. J Appl Physiol 99:1880–1884. doi: 10.1152/japplphysiol.00559.2005
- Stagg CJ, Jayaram G, Pastor D, Kincses ZT, Matthews PM, Johansen-Berg H (2011) Polarity and timing-dependent effects of transcranial direct current stimulation in explicit motor learning. Neuropsychologia 49:800–804. doi: 10.1016/j.neuropsychologia.2011.02.009 CrossRefPubMedPubMedCentralGoogle Scholar