title: The effect of paired associative stimulation on fatigue resistance.
abstract: Paired associative stimulation (PAS) is a non-invasive stimulation method developed to induce bidirectional changes in the excitability of the cortical projections to the target muscles. However, very few studies have shown an association between changes in motor evoked potentials (MEP) after PAS and behavioral changes in healthy subjects. In the present study we hypothesized that the functional relevance of PAS can be seen during fatiguing exercise, since there is always a central contribution to the development of fatigue. Transcranial magnetic stimulation was applied over the motor cortex to measure changes in the MEPs of the soleus muscle before and after PAS. Furthermore, fatigue resistance was tested during 15s sustained maximal isometric contractions before and after PAS. On average, fatigue resistance did not change after PAS, however the change in excitability correlated significantly with the change in fatigue resistance.
  
  
  CONCLUSIONS
  Functionality of PAS intervention was not demonstrated in this study. However, the observed relationship between excitability and fatigue resistance suggests that PAS might have affected central fatigue during short maximal contractions.
authors: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland. Electronic address: susanne.kumpulainen@jyu.fi.
authors: Susanne
authors: S
authors: Kumpulainen
authors: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland.
authors: Jussi
authors: J
authors: Peltonen
authors: Sensorimotor Performance Lab, Department of Sport Science, University of Konstanz, Germany.
authors: Markus
authors: M
authors: Gruber
authors: School of Human Movement Studies, University of Queensland, Australia.
authors: Andrew
authors: A
authors: Cresswell
authors: Validia Rehabilitation, Lahti, Finland.
authors: Sinikka
authors: S
authors: Peurala
authors: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland.
authors: Vesa
authors: V
authors: Linnamo
authors: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland.
authors: Janne
authors: J
authors: Avela
mesh_terms: D000328:Adult; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology; D009473:Neuronal Plasticity; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
keywords: Central fatigue; Fatigue; Motor cortex; Paired associative stimulation; Transcranial magnetic stimulation