title: Does Transcranial Alternating Current Stimulation Induce Cerebellum Plasticity? Feasibility, Safety and Efficacy of a Novel Electrophysiological Approach.
abstract: Cerebellum-brain functional connectivity can be shaped through different non-invasive neurostimulation approaches. In this study, we propose a novel approach to perturb the cerebellum-brain functional connectivity by means of transcranial alternating current stimulation (tACS).
  
  
  
  Twenty-five healthy individuals underwent a cerebellar tACS protocol employing different frequencies (10, 50, and 300 Hz) and a sham-tACS over the right cerebellar hemisphere. We measured their after-effects on the motor evoked potential (MEP) amplitude, the cerebellum-brain inhibition (CBI), the long-latency intracortical inhibition (LICI), from the primary motor cortex of both the hemispheres. In addition, we assessed the functional adaptation to a right hand sequential tapping motor task.
  
  
  
  None of the participants had any side-effect. Following 50 Hz-tACS, we observed a clear contralateral CBI weakening, paralleled by a MEP increase with a better adaptation to frequency variations during the sequential tapping. The 300 Hz-tACS induced a contralateral CBI strengthening, without significant MEP and kinematic after-effects. The 10 Hz-tACS conditioning was instead ineffective.
  
  
  
  We may argue that tACS protocols could have interfered with the activity of CBI-sustaining Purkinje cell, affecting motor adaptation. Our safe approach seems promising in studying the cerebellum-brain functional connectivity, with possible implications in neurorehabilitative settings.
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Naro
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Leo
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Russo
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Cannavò
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy; Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Italy.
authors.forename: Demetrio
authors.initials: D
authors.lastname: Milardi
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy.
authors.forename: Placido
authors.initials: P
authors.lastname: Bramanti
authors.affiliation: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy. Electronic address: salbro77@tiscali.it.
authors.forename: Rocco Salvatore
authors.initials: RS
authors.lastname: Calabrò
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D002531:Cerebellum / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: Cerebellum; Cerebellum-brain inhibition; Motor adaptation; Purkinje cell; Transcranial alternating current stimulation; Transcranial magnetic stimulation