title: Simultaneous Brain-Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning.
abstract: The spinal cord participates in the execution of skilled movements by translating high-level cerebral motor representations into musculotopic commands. Yet, the extent to which motor skill acquisition relies on intrinsic spinal cord processes remains unknown. To date, attempts to address this question were limited by difficulties in separating spinal local effects from supraspinal influences through traditional electrophysiological and neuroimaging methods. Here, for the first time, we provide evidence for local learning-induced plasticity in intact human spinal cord through simultaneous functional magnetic resonance imaging of the brain and spinal cord during motor sequence learning. Specifically, we show learning-related modulation of activity in the C6-C8 spinal region, which is independent from that of related supraspinal sensorimotor structures. Moreover, a brain-spinal cord functional connectivity analysis demonstrates that the initial linear relationship between the spinal cord and sensorimotor cortex gradually fades away over the course of motor sequence learning, while the connectivity between spinal activity and cerebellum gains strength. These data suggest that the spinal cord not only constitutes an active functional component of the human motor learning network but also contributes distinctively from the brain to the learning process. The present findings open new avenues for rehabilitation of patients with spinal cord injuries, as they demonstrate that this part of the central nervous system is much more plastic than assumed before. Yet, the neurophysiological mechanisms underlying this intrinsic functional plasticity in the spinal cord warrant further investigations.
authors.affiliation: Functional Neuroimaging Unit, University of Montreal, Montreal, Quebec, Canada; SensoriMotor Rehabilitation Research Team (CIHR), Montreal, Canada.
authors.forename: Shahabeddin
authors.initials: S
authors.lastname: Vahdat
authors.affiliation: Functional Neuroimaging Unit, University of Montreal, Montreal, Quebec, Canada; SensoriMotor Rehabilitation Research Team (CIHR), Montreal, Canada.
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Lungu
authors.affiliation: SensoriMotor Rehabilitation Research Team (CIHR), Montreal, Canada; École Polytechnique de Montréal, Montreal, Quebec, Canada.
authors.forename: Julien
authors.initials: J
authors.lastname: Cohen-Adad
authors.affiliation: INSERM/UPMC, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Marchand-Pauvert
authors.affiliation: SensoriMotor Rehabilitation Research Team (CIHR), Montreal, Canada; INSERM/UPMC, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
authors.affiliation: Functional Neuroimaging Unit, University of Montreal, Montreal, Quebec, Canada; SensoriMotor Rehabilitation Research Team (CIHR), Montreal, Canada.
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
mesh_terms: D001921:Brain / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*; D055815:Young Adult