title: Prominent role of the spinal central pattern generator in the recovery of locomotion after partial spinal cord injuries.
abstract: The re-expression of hindlimb locomotion after complete spinal cord injuries (SCIs) is caused by the presence of a spinal central pattern generator (CPG) for locomotion. After partial SCI, however, the role of this spinal CPG in the recovery of hindlimb locomotion in the cat remains mostly unknown. In the present work, we devised a dual-lesion paradigm to determine its possible contribution after partial SCI. After a partial section of the left thoracic segment T10 or T11, cats gradually recovered voluntary quadrupedal locomotion. Then, a complete transection was performed two to three segments more caudally (T13-L1) several weeks after the first partial lesion. Cats that received intensive treadmill training after the partial lesion expressed bilateral hindlimb locomotion within hours of the complete lesion. Untrained cats however showed asymmetrical hindlimb locomotion with the limb on the side of the partial lesion walking well before the other hindlimb. Thus, the complete spinalization revealed that the spinal CPG underwent plastic changes after the partial lesions, which were shaped by locomotor training. Over time, with further treadmill training, the asymmetry disappeared and a bilateral locomotion was reinstated. Therefore, although remnant intact descending pathways must contribute to voluntary goal-oriented locomotion after partial SCI, the recovery and re-expression of the hindlimb locomotor pattern mostly results from intrinsic changes below the lesion in the CPG and afferent inputs.
authors.affiliation: Multidisciplinary Team in Locomotor Rehabilitation of the Canadian Institutes of Health Research, Department of Physiology, University of Montreal, Montreal, Quebec, Canada H3T 1J4.
authors.forename: Grégory
authors.initials: G
authors.lastname: Barrière
authors.forename: Hugues
authors.initials: H
authors.lastname: Leblond
authors.forename: Janyne
authors.initials: J
authors.lastname: Provencher
authors.forename: Serge
authors.initials: S
authors.lastname: Rossignol
mesh_terms: D000818:Animals; D002415:Cats; D005121:Extremities / Q000503:physiopathology; D005260:Female; D008159:Lumbar Vertebrae; D008297:Male; D009043:Motor Activity; D009473:Neuronal Plasticity; D010805:Physical Conditioning, Animal; D020127:Recovery of Function; D013116:Spinal Cord / Q000473:pathology / Q000503:physiopathology*; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology* / Q000534:rehabilitation; D013904:Thoracic Vertebrae