Step Training-Dependent Plasticity in Spinal Cutaneous Pathways

Côté, Marie-Pascale; Gossard, Jean‐Pierre

doi:10.1523/jneurosci.1486-04.2004

Cited by 99 publications

(53 citation statements)

References 87 publications

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“…Possible mechanisms subserving the permissive action of treadmill training in the re-expression of hindlimb locomotion remain mostly unknown despite recent progress (de Leon et al, 1999;Tillakaratne et al, 2002;Cote et al, 2003;Cote and Gossard, 2004;Ying et al, 2005). The present work provides functional evidence that treadmill training shapes spinal plasticity after partial lesions.…”

Section: Treadmill Training Promotes Spinal Plasticitymentioning

confidence: 53%

“…For instance, hindlimb locomotion after complete and incomplete spinal lesions is increasingly dependent on the proper integration of sensory afferent inputs Steeves, 1995, 1997;Bouyer and Rossignol, 2003) and it has been proposed that a normalization of these inputs is required for the expression of spinal stepping (Cote et al, 2003;Cote and Gossard, 2004). However, changes in neuronal and synaptic properties (Heckmann et al, 2005) and in neuromodulatory systems intrinsic to the spinal cord (de Leon et al, 1999;Giroux et al, 1999Giroux et al, , 2003Chau et al, 2002;Edgerton et al, 1997;Tillakaratne et al, 2002), are undoubtedly also involved.…”

Section: Reorganization Of the Spinal Locomotor Network After Partialmentioning

confidence: 99%

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Prominent Role of the Spinal Central Pattern Generator in the Recovery of Locomotion after Partial Spinal Cord Injuries

Barrière¹,

Leblond²,

Provencher³

et al. 2008

J. Neurosci.

192

138

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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.

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Section: Treadmill Training Promotes Spinal Plasticitymentioning

confidence: 53%

Section: Reorganization Of the Spinal Locomotor Network After Partialmentioning

confidence: 99%

Prominent Role of the Spinal Central Pattern Generator in the Recovery of Locomotion after Partial Spinal Cord Injuries

Barrière¹,

Leblond²,

Provencher³

et al. 2008

J. Neurosci.

192

138

View full text Add to dashboard Cite

show abstract

“…For example, the amplitude of Group Ia fiber-evoked monosynaptic EPSPs (sEPSPs) was higher in trained than non-trained rats that were spinally transected as neonates. Cote and Gossard (2004) reported a reduction in Ia-evoked EPSPs in trained adult spinal cats, but enhanced cutaneous reflexes in trained compared to non-trained spinal cats when stimulating afferents that were thought to be activated during weight-bearing stepping. They also observed that the Group Ib (Golgi tendon organ) disynaptic input to homonymous motoneurons was reversed from inhibition to excitation more frequently in trained than in nontrained cats (Cote et al, 2003).…”

Section: Neurophysiological Plasticity In Response To Trainingmentioning

confidence: 97%

Training locomotor networks

Edgerton

Courtine

Gerasimenko

et al. 2008

Brain Research Reviews

277

205

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For a complete adult spinal rat to regain some weight-bearing stepping capability, it appears that a sequence of specific proprioceptive inputs that are similar, but not identical, from step to step must be generated over repetitive step cycles. Furthermore, these cycles must include the activation of specific neural circuits that are intrinsic to the lumbosacral spinal cord segments. For these sensorimotor pathways to be effective in generating stepping, the spinal circuitry must be modulated to an appropriate excitability level. This level of modulation is sustained from supraspinal input in intact, but not spinal, rats. In a series of experiments with complete spinal rats, we have shown that an appropriate level of excitability of the spinal circuitry can be achieved using widely different means. For example, this modulation level can be acquired pharmacologically, via epidural electrical stimulation over specific lumbosacral spinal cord segments, and/or by use-dependent mechanisms such as step or stand training. Evidence as to how each of these treatments can "tune" the spinal circuitry to a "physiological state" that enables it to respond appropriately to proprioceptive input will be presented. We have found that each of these interventions can enable the proprioceptive input to actually control extensive details that define the dynamics of stepping over a range of speeds, loads, and directions. A series of experiments will be described that illustrate sensory control of stepping and standing after a spinal cord injury and the necessity for the "physiological state" of the spinal circuitry to be modulated within a critical window of excitability for this control to be manifested. The present findings have important consequences not only for our understanding of how the motor pattern for stepping is formed, but also for the design of rehabilitation intervention to restore lumbosacral circuit function in humans following a spinal cord injury.

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“…Given that neither changes in muscle properties (Roy and Acosta, 1986;Roy et al, 1998Roy et al, , 1999 nor regeneration of descending tracts (Joynes et al, 1999;Grillner, 2002) could account for the differences in stepping ability after training, these improvements must stem from plasticity of neurons and circuits involved in stepping that are present in the lumbar spinal cord (Grillner, 2002). Little is known, however, about how the spinal circuitry changes in response to training and how specific changes may contribute to the improved motor performance (Cote et al, 2003;Cote and Gossard, 2004).…”

Section: Introductionmentioning

confidence: 99%

Changes in Motoneuron Properties and Synaptic Inputs Related to Step Training after Spinal Cord Transection in Rats

Petruska¹,

Ichiyama²,

Jindrich³

et al. 2007

J. Neurosci.

139

116

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Although recovery from spinal cord injury is generally meager, evidence suggests that step training can improve stepping performance, particularly after neonatal spinal injury. The location and nature of the changes in neural substrates underlying the behavioral improvements are not well understood. We examined the kinematics of stepping performance and cellular and synaptic electrophysiological parameters in ankle extensor motoneurons in nontrained and treadmill-trained rats, all receiving a complete spinal transection as neonates. For comparison, electrophysiological experiments included animals injured as young adults, which are far less responsive to training. Recovery of treadmill stepping was associated with significant changes in the cellular properties of motoneurons and their synaptic input from spinal white matter [ipsilateral ventrolateral funiculus (VLF)] and muscle spindle afferents. A strong correlation was found between the effectiveness of step training and the amplitude of both the action potential afterhyperpolarization and synaptic inputs to motoneurons (from peripheral nerve and VLF). These changes were absent if step training was unsuccessful, but other spinal projections, apparently inhibitory to step training, became evident. Greater plasticity of axonal projections after neonatal than after adult injury was suggested by anatomical demonstration of denser VLF projections to hindlimb motoneurons after neonatal injury. This finding confirmed electrophysiological measurements and provides a possible mechanism underlying the greater training susceptibility of animals injured as neonates. Thus, we have demonstrated an "age-at-injury"-related difference that may influence training effectiveness, that successful treadmill step training can alter electrophysiological parameters in the transected spinal cord, and that activation of different pathways may prevent functional improvement.

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Step Training-Dependent Plasticity in Spinal Cutaneous Pathways

Cited by 99 publications

References 87 publications

Prominent Role of the Spinal Central Pattern Generator in the Recovery of Locomotion after Partial Spinal Cord Injuries

Prominent Role of the Spinal Central Pattern Generator in the Recovery of Locomotion after Partial Spinal Cord Injuries

Training locomotor networks

Changes in Motoneuron Properties and Synaptic Inputs Related to Step Training after Spinal Cord Transection in Rats

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