title: Effects of transcranial magnetic stimulation during voluntary and non-voluntary stepping movements in humans.
abstract: Here, we compared motor evoked potentials (MEP) in response to transcranial magnetic stimulation of the motor cortex and the H-reflex during voluntary and vibration-induced air-stepping movements in humans. Both the MEPs (in mm biceps femoris, rectus femoris and tibialis anterior) and H-reflex (in m soleus) were significantly smaller during vibration-induced cyclic leg movements at matched amplitudes of angular motion and muscle activity. These findings highlight differences between voluntary and non-voluntary activation of the spinal pattern generator circuitry in humans, presumably due to an extra facilitatory effect of voluntary control/triggering of stepping on spinal motoneurons and interneurons. The results support the idea of active engagement of supraspinal motor areas in developing central pattern generator-modulating therapies.
authors.affiliation: Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia. Electronic address: solopova@iitp.ru.
authors.forename: I A
authors.initials: IA
authors.lastname: Solopova
authors.affiliation: Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Selionov
authors.affiliation: Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
authors.forename: O V
authors.initials: OV
authors.lastname: Kazennikov
authors.affiliation: Laboratory of Neuromotor Physiology, Santa Lucia Foundation, Rome, Italy.
authors.forename: Y P
authors.initials: YP
authors.lastname: Ivanenko
mesh_terms: D000328:Adult; D063226:Central Pattern Generators / Q000502:physiology; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000294:innervation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014732:Vibration; D016138:Walking / Q000502:physiology
keywords: Air-stepping; Central pattern generator; H-reflex; Humans; Motor cortex; Transcranial magnetic stimulation