Cha John, Heng Chad, Reinkensmeyer David J, Roy Roland R, Edgerton V Reggie, De Leon Ray D
Department of Biological Science, California State University, Los Angeles, California 90032-8162, USA.
J Neurotrauma. 2007 Jun;24(6):1000-12. doi: 10.1089/neu.2006.0233.
Studies have shown that treadmill training with body weight support is effective for enhancing locomotor recovery following a complete spinal cord transection (ST) in animals. However, there have been no studies that have investigated the extent that functional recovery in ST animals is dependent on the amount of activity imposed on the hindlimbs during training. In rats transected as neonates (P5), we used a robotic device to impose either a high or a low amount of hindlimb activity during treadmill training starting 23 days after transection. The rats were trained 5 days per week for 4 weeks. One group (n = 13) received 1000 steps/training session and a second group (n = 13) received 100 steps/training session. During training, the robotic device imposed the maximum amount of weight that each rat could bear on the hindlimbs, and counted the number of stepping movements during each session. After 4 weeks of training, the number of steps performed during treadmill testing was not significantly different between the two groups. However, the quality of stepping in the group that received 1000 steps/training session improved over a range of levels of weight bearing on the hindlimbs and at different treadmill speeds. In contrast, little improvement in the quality of stepping was observed in the group that received only 100 steps/training session. These findings indicate that the ability of the lumbar spinal cord to adjust to load- and speed-related sensory stimuli associated with stepping is dependent on the number of repetitions of the same activity that is imposed on the spinal circuits during treadmill training.
研究表明，体重支持下的跑步机训练对于促进动物完全脊髓横断（ST）后的运动功能恢复有效。然而，尚无研究调查ST动物的功能恢复程度在多大程度上依赖于训练期间施加在后肢上的活动量。在新生期（P5）横断脊髓的大鼠中，我们使用一种机器人装置，在横断后23天开始的跑步机训练期间，对后肢施加高或低的活动量。大鼠每周训练5天，共训练4周。一组（n = 13）每次训练接受1000步，另一组（n = 13）每次训练接受100步。在训练过程中，机器人装置施加每只大鼠后肢能够承受的最大重量，并计算每次训练期间的踏步动作数量。训练4周后，两组在跑步机测试期间执行的步数没有显著差异。然而，每次训练接受1000步的组在一系列后肢负重水平和不同跑步机速度下，踏步质量均有所改善。相比之下，每次训练仅接受100步的组在踏步质量上几乎没有改善。这些发现表明，腰脊髓适应与踏步相关的负荷和速度相关感觉刺激的能力取决于跑步机训练期间施加在脊髓回路的相同活动的重复次数。
