Retention of hindlimb stepping ability in adult spinal cats after the cessation of step training
Retention of hindlimb stepping ability in adult spinal cats after the cessation of step training
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DOI：
10.1152/jn.1999.81.1.85
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发表时间：
1999-01-01
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
成年脊髓猫在跑步机上进行双足后肢运动训练6-12周。在每只动物获得行走能力后，停止运动训练，并在训练结束后6周和12周重新检查行走。的性能特点，后肢肌肉肌电图活动模式，并与培训获得的步骤周期的运动学特征在很大程度上保持训练时被扣留6周。然而，在12周不训练后，运动表现下降，即，绊倒更频繁，并且在任何跑步机速度下持续执行全负重步骤的能力下降。此外，在摆动阶段的爪被抬起的高度下降，和一个较小的范围内的伸展在后肢发生在E3阶段的立场。当三个脊髓猫进行1周的再训练，步进能力恢复得更快，比最初训练。在训练的成年脊髓猫的步进能力可以持续6周没有训练的发现提供了进一步的证据，训练诱导的增强的步进是在脊髓猫学习和增强的步进的记忆存储在脊髓网络。然而，如果12周内不练习这项任务，脊髓似乎会忘记如何始终如一地执行步进。再培训中出现的更快的学习也与学习现象相一致。这些结果与我们早期的发现相结合，表明执行运动任务的神经通路的功效高度依赖于这些通路的周期性激活，这些通路的激活顺序与运动任务相一致。
Adult spinal cats were trained to perform bipedal hindlimb locomotion on a treadmill for 6-12 wk. After each animal acquired the ability to step, locomotor training was withheld, and stepping was reexamined 6 and 12 wk after training ended. The performance characteristics, hindlimb muscle electromyographic activity patterns, and kinematic characteristics of the step cycle that were acquired with training were largely maintained when training was withheld for 6 wk. However, after 12 wk without training, locomotor performance declined, i.e., stumbling was more frequent, and the ability to consistently execute full weight-bearing steps at any treadmill speed decreased. In addition, the height that the paw was lifted during the swing phase decreased, and a smaller range of extension in the hindlimbs occurred during the E3 phase of stance. When three of the spinal cats underwent 1 wk of retraining, stepping ability was regained more rapidly than when trained initially. The finding that stepping ability in trained adult spinal cats can persist for 6 wk without training provides further evidence that training-induced enhancement of stepping is learned in the spinal cats and that a memory of the enhanced stepping is stored in the spinal networks. However, it appears that the spinal cord can forget how to consistently execute stepping if that task is not practiced for 12 wk. The more rapid learning that occurred with retraining is also consistent with a learning phenomenon. These results in conjunction with our earlier findings suggest that the efficacy of the neural pathways that execute a motor task is highly dependent on the periodic activation of those pathways in a sequence compatible with that motor task.