Danny Spampinato1, Esin Avci2, John Rothwell3, Lorenzo Rocchi3. 1. Department of Clinical and Movement Neurosciences, Institute of Neurology, University College London, United Kingdom; Non-invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, 00142, Rome, Italy. Electronic address: d.spampinato@ucl.ac.uk. 2. Department of Sport and Sport Science, Institute of Biology, University of Freiburg, Germany. 3. Department of Clinical and Movement Neurosciences, Institute of Neurology, University College London, United Kingdom.
Abstract
BACKGROUND: it is well-known that the cerebellum is critical for the integrity of motor and cognitive actions. Applying non-invasive brain stimulation techniques over this region results in neurophysiological and behavioural changes, which have been associated with the modulation of cerebellar-cerebral cortex connectivity. Here, we investigated whether online application of cerebellar transcranial alternating current stimulation (tACS) results in changes to this pathway. METHODS: thirteen healthy individuals participated in two sessions of cerebellar tACS delivered at different frequencies (5Hz and 50Hz). We used transcranial magnetic stimulation to measure cerebellar-motor cortex (M1) inhibition (CBI), short-intracortical inhibition (SICI) and short-afferent inhibition (SAI) before, during and after the application of tACS. RESULTS: we found that CBI was specifically strengthened during the application of 5Hz cerebellar tACS. No changes were detected immediately following the application of 5Hz stimulation, nor at any time point with 50Hz stimulation. We also found no changes to M1 intracortical circuits (i.e. SICI) or sensorimotor interaction (i.e. SAI), indicating that the effects of 5Hz tACS over the cerebellum are site-specific. CONCLUSIONS: cerebellar tACS can modulate cerebellar excitability in a time- and frequency-dependent manner. Additionally, cerebellar tACS does not appear to induce any long-lasting effects (i.e. plasticity), suggesting that stimulation enhances oscillations within the cerebellum only throughout the stimulation period. As such, cerebellar tACS may have significant implications for diseases manifesting with abnormal cerebellar oscillatory activity and also for future behavioural studies.
BACKGROUND: it is well-known that the cerebellum is critical for the integrity of motor and cognitive actions. Applying non-invasive brain stimulation techniques over this region results in neurophysiological and behavioural changes, which have been associated with the modulation of cerebellar-cerebral cortex connectivity. Here, we investigated whether online application of cerebellar transcranial alternating current stimulation (tACS) results in changes to this pathway. METHODS: thirteen healthy individuals participated in two sessions of cerebellar tACS delivered at different frequencies (5Hz and 50Hz). We used transcranial magnetic stimulation to measure cerebellar-motor cortex (M1) inhibition (CBI), short-intracortical inhibition (SICI) and short-afferent inhibition (SAI) before, during and after the application of tACS. RESULTS: we found that CBI was specifically strengthened during the application of 5Hz cerebellar tACS. No changes were detected immediately following the application of 5Hz stimulation, nor at any time point with 50Hz stimulation. We also found no changes to M1 intracortical circuits (i.e. SICI) or sensorimotor interaction (i.e. SAI), indicating that the effects of 5Hz tACS over the cerebellum are site-specific. CONCLUSIONS: cerebellar tACS can modulate cerebellar excitability in a time- and frequency-dependent manner. Additionally, cerebellar tACS does not appear to induce any long-lasting effects (i.e. plasticity), suggesting that stimulation enhances oscillations within the cerebellum only throughout the stimulation period. As such, cerebellar tACS may have significant implications for diseases manifesting with abnormal cerebellar oscillatory activity and also for future behavioural studies.
Authors: P M Rossini; A T Barker; A Berardelli; M D Caramia; G Caruso; R Q Cracco; M R Dimitrijević; M Hallett; Y Katayama; C H Lücking Journal: Electroencephalogr Clin Neurophysiol Date: 1994-08
Authors: T Kujirai; M D Caramia; J C Rothwell; B L Day; P D Thompson; A Ferbert; S Wroe; P Asselman; C D Marsden Journal: J Physiol Date: 1993-11 Impact factor: 5.182
Authors: John-Stuart Brittain; Hayriye Cagnan; Arpan R Mehta; Tabish A Saifee; Mark J Edwards; Peter Brown Journal: J Neurosci Date: 2015-01-14 Impact factor: 6.167
Authors: Maximilian J Wessel; Laurijn R Draaisma; Anne F W de Boer; Chang-Hyun Park; Pablo Maceira-Elvira; Manon Durand-Ruel; Philipp J Koch; Takuya Morishita; Friedhelm C Hummel Journal: Sci Rep Date: 2020-07-08 Impact factor: 4.379
Authors: Z Cattaneo; C Ferrari; A Ciricugno; E Heleven; D J L G Schutter; M Manto; F Van Overwalle Journal: Cerebellum Date: 2021-07-16 Impact factor: 3.847
Authors: Rebecca Herzog; Till M Berger; Martje G Pauly; Honghu Xue; Elmar Rueckert; Alexander Münchau; Tobias Bäumer; Anne Weissbach Journal: Front Neurosci Date: 2022-09-15 Impact factor: 5.152