Muscle Plasticity in Rat Following Spinal Transection and Chronic Intraspinal Microstimulation
Muscle Plasticity in Rat Following Spinal Transection and Chronic Intraspinal Microstimulation
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DOI：
10.1109/tnsre.2010.2052832
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发表时间：
2011-02-01
影响因子：
4.9
通讯作者：
Mushahwar, Vivian K.
中科院分区：
文献类型：
--
作者：
Bamford, Jeremy A.;Putman, Charles T.;Mushahwar, Vivian K.
椎管内微刺激（ISMS）利用腹侧灰质的电刺激来重新激活瘫痪的骨骼肌。这项工作评估了股四头肌在完全横断和使用 ISMS 或标准神经袖带 (NCS) 进行慢性刺激后发生的变化。刺激持续 30 天，每天 4 小时。与完整对照 (IC) 相比，两种方法均导致张力峰值时间（ISMS 35%、NCS 25%）和半上升时间（ISMS 39%、NCS 25%）显着增加。与 IC 相比，IIA 型肌球蛋白重链 (MHC) 相应增加，IID 型 MHC 相应减少。这些结果是出乎意料的，因为 ISMS 以接近正常的生理顺序募集运动单位，而 NCS 以相反的顺序募集运动单位。脊髓横断和 30 天的刺激并没有改变任何一种募集情况。横断后和刺激 30 天后通过 ISMS 获得的力募集曲线的斜率与在完整动物中获得的相似，并且比通过 NCS 获得的斜率浅 3.4 倍。当前工作中观察到的转变可以通过接近最大水平的运动单位募集、每日总活动时间和刺激范式的强直性质来最好地解释。
Intraspinal microstimulation (ISMS) employs electrical stimulation of the ventral grey matter to reactivate paralyzed skeletal muscle. This work evaluated the transformations in the quadriceps muscle that occurred following complete transection and chronic stimulation with ISMS or a standard nerve cuff (NCS). Stimulation was applied for 30 days, 4 h/day. Both methods induced significant increases in time-to-peak tension (ISMS 35%, NCS 25%) and half rise-time (ISMS 39%, NCS 25%) compared to intact controls (IC). Corresponding increases in type-IIA myosin heavy chain (MHC) and decreases in type-IID MHC were noted compared to IC. These results were unexpected because ISMS recruits motor units in a near-normal physiological order while NCS recruits motor units in a reversed order. Spinal cord transection and 30 days of stimulation did not alter either recruitment profile. The slope of the force recruitment curves obtained through ISMS following transection and 30 days of stimulation was similar to that obtained in intact animals, and 3.4-fold shallower than that obtained through NCS. The transformations observed in the current work are best explained by the near maximal level of motor unit recruitment, the total daily time of activity and the tonic nature of the stimulation paradigm.