title: Promoting Motor Cortical Plasticity with Acute Aerobic Exercise: A Role for Cerebellar Circuits.
abstract: Acute aerobic exercise facilitated long-term potentiation-like plasticity in the human primary motor cortex (M1). Here, we investigated the effect of acute aerobic exercise on cerebellar circuits, and their potential contribution to altered M1 plasticity in healthy individuals (age: 24.8 ± 4.1 years). In Experiment   1, acute aerobic exercise reduced cerebellar inhibition (CBI) (n = 10, p = 0.01), elicited by dual-coil paired-pulse transcranial magnetic stimulation. In Experiment   2, we evaluated the facilitatory effects of aerobic exercise on responses to paired associative stimulation, delivered with a 25 ms (PAS25) or 21 ms (PAS21) interstimulus interval (n = 16 per group). Increased M1 excitability evoked by PAS25, but not PAS21, relies on trans-cerebellar sensory pathways. The magnitude of the aerobic exercise effect on PAS response was not significantly different between PAS protocols (interaction effect: p = 0.30); however, planned comparisons indicated that, relative to a period of rest, acute aerobic exercise enhanced the excitatory response to PAS25 (p = 0.02), but not PAS21 (p = 0.30). Thus, the results of these planned comparisons indirectly provide modest evidence that modulation of cerebellar circuits may contribute to exercise-induced increases in M1 plasticity. The findings have implications for developing aerobic exercise strategies to "prime" M1 plasticity for enhanced motor skill learning in applied settings.
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Cameron S
authors.initials: CS
authors.lastname: Mang
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Katlyn E
authors.initials: KE
authors.lastname: Brown
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Jason L
authors.initials: JL
authors.lastname: Neva
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Snow
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Campbell
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3; Graduate Program in Neuroscience, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Lara A
authors.initials: LA
authors.lastname: Boyd
mesh_terms: D000328:Adult; D002531:Cerebellum / Q000502:physiology*; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult