Locomotor capacity attributable to step training versus spontaneous recovery after spinalization in adult cats
Locomotor capacity attributable to step training versus spontaneous recovery after spinalization in adult cats
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DOI：
10.1152/jn.1998.79.3.1329
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发表时间：
1998-03-01
影响因子：
2.5
通讯作者：
Edgerton, VR
中科院分区：
文献类型：
--
作者：
de Leon, RD;Hodgson, JA;Edgerton, VR
本实验研究了成年雌性脊髓猫在踏步过程中的运动性能、后肢肌肉活动和步态模式。相对于prespinalization双足和四足步进模式的运动特征的变化被用来评估的影响，步骤训练的能力，执行充分的负重步进spinalization后。步训练包括在运动恢复的任何给定阶段，以最大范围的跑步机速度进行后肢的完全负重踏步。在训练的初始阶段，根据需要辅助肢体执行成功的步骤。基于两个行为标准，跑步机步进的最大速度和单位时间内成功的步数，训练步进的动物的步进能力比允许自发恢复的动物至少大3倍，即，未受过训练的人。更大的成功，在步进反映在几个生理和运动学特性。例如，在胫骨前肌（踝背屈肌）的肌电图（EMG）爆发的幅度，在步骤周期的站立（E3）和摆动（El）阶段结束时的伸展量，以及在摆动过程中后肢的提升量，在步骤训练的脊髓猫比非训练的脊髓猫更大。训练后发生的变化反映了在步周期的特定阶段的功能适应，例如，增强的屈肌和伸肌功能。归因于步训练的改进的步进能力被解释为以时间上适当的方式激活适当的神经元的概率的变化。这种解释，反过来，表明步骤训练促进或加强了现有的感觉运动通路的功能，而不是促进额外的途径的产生。这些结果表明，成人腰髓在一定速度范围内产生完全负重行走的能力在很大程度上是由脊髓上连接被消除后的脊髓功能体验所定义的。这些结果对于以下方面具有明显的意义：1）运动学习发生在脊髓中的可能性; 2）在评估任何脊髓化后干预的效果时考虑“运动体验”的重要性; 3）使用依赖性干预促进和增强运动恢复。
Locomotor performance, hindlimb muscle activity and gait patterns during stepping were studied in step-trained and nontrained female, adult spinal cats. Changes in locomotor characteristics relative to prespinalization bipedal and quadrupedal stepping patterns were used to evaluate the effects of step training on the capacity to execute full weight-bearing stepping after spinalization. Step training consisted of full weight-bearing stepping of the hind-limbs at the greatest range of treadmill speeds possible at any given stage of locomotor recovery. In the initial stages of training the limbs were assisted as needed to execute successful steps. On the basis of two behavioral criteria, the maximum speed of treadmill stepping and the number of successful steps per unit time, the ability to step was at least 3 times greater in animals trained to step versus those allowed to recover spontaneously, i.e., the non-trained. The greater success in stepping was reflected in several physiological and kinematic properties. For example, the amplitude of electromyograph (EMG) bursts in the tibialis anterior (an ankle dorsiflexor), the amount of extension at the end of both the stance (E3) and swing (El) phases of the step cycle, and the amount of lift of the hindlimb during swing were greater in step-trained than in nontrained spinal cats. The changes that occurred in response to training reflected functional adaptations at specific phases of the step cycle, eg, enhanced flexor and extensor function. The improved stepping capacity attributable to step training is interpreted as a change in the probability of the appropriate neurons being activated in a temporally appropriate manner. This interpretation, in turn, suggests that step training facilitated or reinforced the function of extant sensorimotor pathways rather than promoting the generation of additional pathways. These results show that the capacity of the adult lumbar spinal cord to generate full weight-bearing stepping over a range of speeds is defined, in large part, by the functional experience of the spinal cord after supraspinal connectivity has been eliminated. These results have obvious implications with regards to 1) the possibility of motor learning occurring in the spinal cord; 2) the importance of considering "motor experience" in assessing the effect of any post-spinalization intervention; and 3) the utilization of use-dependent interventions in facilitating and enhancing motor recovery.