Discordance in Recovery Between Altered Locomotion and Muscle Atrophy Induced by Simulated Microgravity in Rats

ABSTRACTExposure to a microgravity environment leads to adverse effects in motion and musculoskeletal properties. However, few studies have investigated the recovery of altered locomotion and muscle atrophy simultaneously. The authors investigated altered locomotion in rats submitted to simulated microgravity by hindlimb unloading for 2 weeks. Motion deficits were characterized by hyperextension of the knees and ankle joints and forward-shifted limb motion. Furthermore, these locomotor deficits did not revert to their original form after a 2-week recovery period, although muscle atrophy in the hindlimbs had recovered, implying discordance in recovery between altered locomotion and muscle atrophy, and that other factors such as neural drives might control behavioral adaptations to microgravity.

摘要：微重力环境暴露会对运动能力及肌肉骨骼特性造成不良影响。然而，目前鲜有研究同时探究运动模式改变与肌肉萎缩的恢复过程。本研究针对通过后肢悬吊法模拟2周微重力环境的大鼠，对其运动模式改变情况进行了考察。研究发现，运动功能缺损表现为膝关节与踝关节过度伸展，以及肢体运动前移。进一步观察显示，尽管后肢肌肉萎缩已在恢复期恢复至初始状态，但上述运动功能缺损在2周恢复期后并未得到改善，这表明运动模式改变与肌肉萎缩的恢复进程并不一致，同时提示诸如神经驱动等其他因素可能参与调控机体对微重力环境的行为适应性改变。