Spinal cord reflexes induced by epidural spinal cord stimulation in normal awake rats
Spinal cord reflexes induced by epidural spinal cord stimulation in normal awake rats
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DOI：
10.1016/j.jneumeth.2006.05.004
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发表时间：
2006-10-30
影响因子：
3
通讯作者：
Edgerton, V. Reggie
中科院分区：
文献类型：
--
作者：
Gerasimenko, Yury P.;Lavrov, Igor A.;Edgerton, V. Reggie
本文研究了正常清醒大鼠双足站立时，硬膜外脊髓电刺激引起的后肢肌肉运动反应。在L2或S1刺激引起股外侧肌，半腱肌，胫骨前肌和内侧腓肠肌的同时和双边的反应。刺激S1诱发早期（ER）、中期（MR）和晚期（LR）反应：刺激L2仅诱发MR和LR。振动和双硬膜外刺激试验表明，ER是一个直接的运动反应，而MR和LR介导的突触。MR具有单突触反射的特性，即，在振动期间被抑制，在双重刺激的第二脉冲期间被抑制。LR的某些成分似乎是由与屈肌反射相关的传入神经介导的，并且可能涉及II组传入神经。在双足踏车步进，MR调制伸肌，而LR调制屈肌。这些结果表明，在运动过程中屈肌和伸肌运动池的单突触和多突触反射的差异调制。在L2或S1刺激的单突触反应一般被放大伸肌在站立阶段和屈肌在摆动阶段的步骤周期。没有相关性被发现之间的ER和EMG背景在步进，而MR和LR的变化密切相关，在相应的肌肉的EMG活动水平。这些数据表明，使用硬膜外刺激检查单突触和多突触通路的运动池与多个肌肉在运动过程中，并在很长一段时间内的可行性。(c)2006 Elsevier B.V.保留所有权利。
Motor responses in hindlimb muscles to epidural spinal cord stimulation in normal awake rats during bipedal standing were studied. Stimulation at L2 or S1 induced simultaneous and bilateral responses in the vastus lateralis, semitendinosus, tibialis anterior, and medial gastrocnemius muscles. Stimulation at S1 evoked an early (ER), middle (MR) and late (LR) response: stimulation at L2 elicited only a MR and LR. Vibration and double epidural stimulation testing suggests that the ER is a direct motor response, whereas the MR and LR are mediated synaptically. MR has properties of a monosynalptic reflex, i.e., inhibited during vibration and depressed during the second pulse of a double stimulation., Some components of the LR seem to be mediated by afferents associated with the flexor reflex and probably involve group II afferents. During bipedal treadmill stepping, the MR was modulated in extensors, whereas the LR was modulated in flexors. These results show differential modulation of monosynaptic and polysynaptic reflexes in flexor and extensor motor pools during locomotion. Monosynaptic responses to stimulation at either L2 or S1 generally were amplified in extensors during the stance phase and in flexors during the swing phase of the step cycle. No correlation was found between the ER and the EMG background during stepping, whereas both the MR and LR were closely correlated with the changes in the EMG activity level of the corresponding muscle. These data demonstrate the feasibility of using epidural stimulation for examining monosynaptic and polysynaptic pathways to motor pools associated with multiple muscles during movement and over a prolonged period. (c) 2006 Elsevier B.V. All rights reserved.