title: Causal evidence that intrinsic beta-frequency is relevant for enhanced signal propagation in the motor system as shown through rhythmic TMS.
abstract: Correlative evidence provides support for the idea that brain oscillations underpin neural computations. Recent work using rhythmic stimulation techniques in humans provide causal evidence but the interactions of these external signals with intrinsic rhythmicity remain unclear. Here, we show that sensorimotor cortex follows externally applied rhythmic TMS (rTMS) stimulation in the beta-band but that the elicited responses are strongest at the intrinsic individual beta peak frequency. While these entrainment effects are of short duration, even subthreshold rTMS pulses propagate through the network and elicit significant cortico-spinal coupling, particularly when stimulated at the individual beta-frequency. Our results show that externally enforced rhythmicity interacts with intrinsic brain rhythms such that the individual peak frequency determines the effect of rTMS. The observed downstream spinal effect at the resonance frequency provides evidence for the causal role of brain rhythms for signal propagation.
authors.affiliation: Wellcome Trust Centre for Neuroimaging at UCL, Institute of Neurology, University College London, London, UK; UCL Institute of Cognitive Neuroscience, University College London, London, UK; Department of Psychology, Centre for Brain Science, University of Essex, Colchester, UK. Electronic address: vromei@essex.ac.uk.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Romei
authors.affiliation: Wellcome Trust Centre for Neuroimaging at UCL, Institute of Neurology, University College London, London, UK; UCL Institute of Cognitive Neuroscience, University College London, London, UK; School of Psychology, The University of Nottingham, Nottingham, UK.
authors.forename: Markus
authors.initials: M
authors.lastname: Bauer
authors.affiliation: UCL Institute of Cognitive Neuroscience, University College London, London, UK; School of Psychology, University of Kent, Canterbury, UK.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Brooks
authors.affiliation: Wellcome Trust Centre for Neuroimaging at UCL, Institute of Neurology, University College London, London, UK.
authors.forename: Marcos
authors.initials: M
authors.lastname: Economides
authors.affiliation: Wellcome Trust Centre for Neuroimaging at UCL, Institute of Neurology, University College London, London, UK.
authors.forename: Will
authors.initials: W
authors.lastname: Penny
authors.affiliation: Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.
authors.forename: Gregor
authors.initials: G
authors.lastname: Thut
authors.affiliation: Wellcome Trust Centre for Neuroimaging at UCL, Institute of Neurology, University College London, London, UK; UCL Institute of Cognitive Neuroscience, University College London, London, UK.
authors.forename: Jon
authors.initials: J
authors.lastname: Driver
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, UK.
authors.forename: Sven
authors.initials: S
authors.lastname: Bestmann
mesh_terms: D000328:Adult; D001611:Beta Rhythm / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult