title: Anodal transcranial direct current stimulation of the motor cortex increases cortical voluntary activation and neural plasticity.
abstract: We examined the cumulative effect of 4 consecutive bouts of noninvasive brain stimulation on corticospinal plasticity and motor performance, and whether these responses were influenced by the brain-derived neurotrophic factor (BDNF) polymorphism.
  
  
  
  In a randomized double-blinded cross-over design, changes in strength and indices of corticospinal plasticity were analyzed in 14 adults who were exposed to 4 consecutive sessions of anodal and sham transcranial direct current stimulation (tDCS). Participants also undertook a blood sample for BDNF genotyping (N = 13).
  
  
  
  We observed a significant increase in isometric wrist flexor strength with transcranial magnetic stimulation revealing increased corticospinal excitability, decreased silent period duration, and increased cortical voluntary activation compared with sham tDCS.
  
  
  
  The results show that 4 consecutive sessions of anodal tDCS increased cortical voluntary activation manifested as an improvement in strength. Induction of corticospinal plasticity appears to be influenced by the BDNF polymorphism. Muscle Nerve 54: 903-913, 2016.
authors.affiliation: Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia.
authors.forename: Ashlyn
authors.initials: A
authors.lastname: Frazer
authors.affiliation: Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Williams
authors.affiliation: Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Spittles
authors.affiliation: Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne, Australia.
authors.forename: Timo
authors.initials: T
authors.lastname: Rantalainen
authors.affiliation: Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Melbourne, Australia. d.kidgell@latrobe.edu.au.
authors.forename: Dawson
authors.initials: D
authors.lastname: Kidgell
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000235:genetics / Q000502:physiology*; D005260:Female; D005838:Genotype; D006801:Humans; D007537:Isometric Contraction / Q000235:genetics; D008297:Male; D008715:Methionine / Q000235:genetics; D009044:Motor Cortex / Q000502:physiology*; D053580:Muscle Strength; D009154:Mutation / Q000235:genetics; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000235:genetics / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D065908:Transcranial Direct Current Stimulation; D050781:Transcranial Magnetic Stimulation; D014633:Valine / Q000235:genetics; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine
keywords: BDNF polymorphism; cortical voluntary activation; motor performance; neural plasticity; strength; transcranial direct current stimulation