Changes in cortico-spinal excitability following uphill versus downhill treadmill exercise.
An acute bout of aerobic exercise induces neuroplasticity in the motor cortex. Moreover, paired associative stimulation (PAS) is known to induce neuroplasticity in M1. However, the possible influence of the type of exercise on the neuroplastic changes remains unknown. The present study investigated the effects of two different modes of muscle contraction produced during locomotor exercise on changes in corticospinal (CS) excitability. Subjects performed two 30-min treadmill exercises at an intensity corresponding to 60% of their maximal heart rate with either a +10% (uphill) or -10% (downhill) slope. These exercises were followed or not by paired associative stimulation method (PAS25) which consisted of 200 paired stimuli (0.25Hz, 15min) of median nerve electrical stimulation followed by transcranial magnetic stimulation of the hand M1 area (ISI 25ms). Motor evoked potentials (MEP), assessed through abductor pollicis brevis (APB) activity were obtained before exercise, at 5min, 15min and 30min after exercise. A significant (P<0.05) increase of the MEP amplitude was observed 30min after both exercises but was not different between the two modes of locomotion. On the contrary, MEP amplitude with PAS25increased only 30min after downhill exercise. We conclude that sub-maximal treadmill exercise increases CS excitability within a period of 30min. However, the predominant mode of muscle contraction during uphill versus downhill locomotion does not influence CS excitability when assessed using a non-exercised muscle. However, results from PAS25suggest that specific neuroplastic changes occur likely due to homeostatic mechanisms induced by exercise plus a PAS protocol.
INSERM CAPS UMR 1093, F-21000 Dijon, France; University Bourgogne-Franche Comté, CAPS UMR 1093, F-21000 Dijon, France. Electronic address: yoann.garnier@u-bourgogne.fr.
Yoann M
YM
Garnier
INSERM CAPS UMR 1093, F-21000 Dijon, France; University Bourgogne-Franche Comté, CAPS UMR 1093, F-21000 Dijon, France. Electronic address: romuald.lepers@u-bourgogne.fr.
Romuald
R
Lepers
Neural Control of Movement Laboratory, School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia. Electronic address: pstapley@uow.edu.au.
Paul J
PJ
Stapley
INSERM CAPS UMR 1093, F-21000 Dijon, France; University Bourgogne-Franche Comté, CAPS UMR 1093, F-21000 Dijon, France. Electronic address: papaxant@u-bourgogne.fr.
Charalambos
C
Papaxanthis
INSERM CAPS UMR 1093, F-21000 Dijon, France; University Bourgogne-Franche Comté, CAPS UMR 1093, F-21000 Dijon, France; Centre for Performance Expertise, UFR STAPS, Université de Bourgogne Dijon, France. Electronic address: christos.paizis@u-bourgogne.fr.
Christos
C
Paizis
D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007717:Knee / Q000294:innervation; D008124:Locomotion / Q000502:physiology; D008297:Male; D008475:Median Nerve / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology*; D012119:Respiration; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
Downhill; Paired associative stimulation; Transcranial magnetic stimulation; Treadmill running; Treadmill walking; Uphill