title: Muscle spindle feedback directs locomotor recovery and circuit reorganization after spinal cord injury.
abstract: Spinal cord injuries alter motor function by disconnecting neural circuits above and below the lesion, rendering sensory inputs a primary source of direct external drive to neuronal networks caudal to the injury. Here, we studied mice lacking functional muscle spindle feedback to determine the role of this sensory channel in gait control and locomotor recovery after spinal cord injury. High-resolution kinematic analysis of intact mutant mice revealed proficient execution in basic locomotor tasks but poor performance in a precision task. After injury, wild-type mice spontaneously recovered basic locomotor function, whereas mice with deficient muscle spindle feedback failed to regain control over the hindlimb on the lesioned side. Virus-mediated tracing demonstrated that mutant mice exhibit defective rearrangements of descending circuits projecting to deprived spinal segments during recovery. Our findings reveal an essential role for muscle spindle feedback in directing basic locomotor recovery and facilitating circuit reorganization after spinal cord injury.
authors.affiliation: Biozentrum, Department of Cell Biology, University of Basel, 4056 Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.
authors.forename: Aya
authors.initials: A
authors.lastname: Takeoka
authors.affiliation: Brain Mind Institute and Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Isabel
authors.initials: I
authors.lastname: Vollenweider
authors.affiliation: Brain Mind Institute and Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Grégoire
authors.initials: G
authors.lastname: Courtine
authors.affiliation: Biozentrum, Department of Cell Biology, University of Basel, 4056 Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland. Electronic address: silvia.arber@unibas.ch.
authors.forename: Silvia
authors.initials: S
authors.lastname: Arber
mesh_terms: D000818:Animals; D051776:Early Growth Response Protein 3 / Q000235:genetics / Q000378:metabolism; D025461:Feedback, Physiological; D008124:Locomotion; D051379:Mice; D009470:Muscle Spindles / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D013119:Spinal Cord Injuries / Q000378:metabolism; D058630:Spinal Cord Regeneration
chemical_list: C497369:Egr3 protein, mouse; D051776:Early Growth Response Protein 3