title: Reversed Effects of Intermittent Theta Burst Stimulation following Motor Training That Vary as a Function of Training-Induced Changes in Corticospinal Excitability.
abstract: Intermittent theta burst stimulation (iTBS) has the potential to enhance corticospinal excitability (CSE) and subsequent motor learning. However, the effects of iTBS following motor learning are unknown. The purpose of the present study was to explore the effect of iTBS on CSE and performance following motor learning. Therefore twenty-four healthy participants practiced a ballistic motor task for a total of 150 movements. iTBS was subsequently applied to the trained motor cortex (STIM group) or the vertex (SHAM group). Performance and CSE were assessed before motor learning and before and after iTBS. Training significantly increased performance and CSE in both groups. In STIM group participants, subsequent iTBS significantly reduced motor performance with smaller reductions in CSE. CSE changes as a result of motor learning were negatively correlated with both the CSE changes and performance changes as a result of iTBS. No significant effects of iTBS were found for SHAM group participants. We conclude that iTBS has the potential to degrade prior motor learning as a function of training-induced CSE changes. That means the expected LTP-like effects of iTBS are reversed following motor learning.
authors.affiliation: Human Motor Control Laboratory, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS 7001, Australia ; Sport & Exercise Psychology Unit, Department of Sport Science, University of Rostock, Ulmenstraße 69, 18057 Rostock, Germany.
authors.forename: Tino
authors.initials: T
authors.lastname: Stöckel
authors.affiliation: Human Motor Control Laboratory, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS 7001, Australia ; Research Institute for Sports and Exercise Sciences, Faculty of Science, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool L3 3AF, UK.
authors.forename: Jeffery J
authors.initials: JJ
authors.lastname: Summers
authors.affiliation: Human Motor Control Laboratory, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS 7001, Australia.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Hinder
mesh_terms: D000328:Adult; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009043:Motor Activity; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult