title: Temporal dynamics of cerebellar and motor cortex physiological processes during motor skill learning.
abstract: Learning motor tasks involves distinct physiological processes in the cerebellum (CB) and primary motor cortex (M1). Previous studies have shown that motor learning results in at least two important neurophysiological changes: modulation of cerebellar output mediated in-part by long-term depression of parallel fiber-Purkinje cell synapse and induction of long-term plasticity (LTP) in M1, leading to transient occlusion of additional LTP-like plasticity. However, little is known about the temporal dynamics of these two physiological mechanisms during motor skill learning. Here we use non-invasive brain stimulation to explore CB and M1 mechanisms during early and late motor skill learning in humans. We predicted that early skill acquisition would be proportional to cerebellar excitability (CBI) changes, whereas later stages of learning will result in M1 LTP-like plasticity modifications. We found that early, and not late into skill training, CBI changed. Whereas, occlusion of LTP-like plasticity over M1 occurred only during late, but not early training. These findings indicate a distinct temporal dissociation in the physiological role of the CB and M1 when learning a novel skill. Understanding the role and temporal dynamics of different brain regions during motor learning is critical to device optimal interventions to augment learning.
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins School of Medicine, 720 Rutland Avenue Baltimore, MD 21205, USA.|Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA.
authors.forename: D
authors.initials: D
authors.lastname: Spampinato
authors.affiliation: Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA.|Department of Neuroscience, Johns Hopkins School of Medicine, 725 North Wolfe Street Baltimore, MD 21205, USA.|Department of Neurology, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA.
authors.forename: P
authors.initials: P
authors.lastname: Celnik
mesh_terms: D000328:Adult; D002531:Cerebellum / Q000502:physiology*; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D007858:Learning; D017774:Long-Term Potentiation; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills; D011597:Psychomotor Performance; D011930:Reaction Time; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult