Magnetically evoked inter-enlargement response: An assessment of ascending propriospinal fibers following spinal cord injury
Magnetically evoked inter-enlargement response: An assessment of ascending propriospinal fibers following spinal cord injury
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DOI：
10.1016/j.expneurol.2006.04.032
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发表时间：
2006-10-01
影响因子：
5.3
通讯作者：
Magnuson, David S. K.
中科院分区：
文献类型：
--
作者：
Beaumont, Eric;Onifer, Stephen M.;Magnuson, David S. K.
本研究的目的是通过定义快速传导（大髓鞘）上行轴突的解剖位置，以及实验脊髓损伤后反应与运动功能之间的关系，来表征一种新的电生理评估——磁诱发间扩反应（MIER）。在磁刺激一侧髋关节后，记录肱三头肌的肌电反应。记录正常对照和不同撕裂伤（背侧、外侧或背侧和外侧半球）或T9水平150千瓦（kd）挫伤后三头肌的短潜伏期（类似于6 ms）肌电图。三头肌MIER的振幅与开阔场地运动时外侧索白质的面积和后肢功能显著相关（r(2) = 0.55）。在完成外侧半切面后，在双侧三头肌中出现了MIERs。咬肌的反应也可以被记录下来，表明这条通路的影响超出了脊髓。在T9时将生物素化右旋糖酐胺（BDA）注射到脊髓一侧侧白质中，发现了双侧分布的本体脊髓通路的解剖学证据。bda标记的轴突呈双侧曲张，分布于颈部增大尾侧区域的中间和腹侧灰质。这些观察结果表明，MIERs可能有助于定量评估实验性脊髓损伤后的神经传递和功能恢复。(c) 2006爱思唯尔公司版权所有。
The aim of the present study was to characterize a novel electrophysiological assessment, the magnetically evoked interenlargement response (MIER), by defining the anatomical location of the fast conducting (large myelinated) ascending axons that mediate the response and the relationship between the response and locomotor function following experimental spinal cord injury. Electromyographic (EMG) responses were recorded from the triceps muscles following magnetic stimulation of one hip. Short-latency (similar to 6 ms) EMGs were recorded from triceps muscles in normal controls and following different laceration injuries (dorsal, lateral or dorsal and lateral hemisections) or a 150-kilodyne (kd) contusion injury at the T9 level. The amplitude of the triceps MIER was significantly correlated to the area of spared white matter in the lateral funiculus and to hindlimb function during open field locomotion (r(2) = 0.55). Following a complete lateral hemisection, MIERs were present in the triceps bilaterally following stimulation of either hip. Responses could also be recorded from the masseter muscles indicating that the influence of this pathway extends beyond the spinal cord. Anatomical evidence of a bilaterally distributed propriospinal pathway was found when biotinylated dextran amine (BDA) was injected into the lateral white matter on one side of the spinal cord at T9. BDA-labeled axons with varicosities were found bilaterally in the intermediate and ventral gray matter of the caudal region of the cervical enlargement. These observations suggest that MIERs may be useful to quantitatively assess neurotransmission and functional recovery over time after experimental spinal cord injury. (c) 2006 Elsevier Inc. All rights reserved.