Functional and electrophysiological changes after graded traumatic spinal cord injury in adult rat
Functional and electrophysiological changes after graded traumatic spinal cord injury in adult rat
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DOI：
10.1016/j.expneurol.2004.08.026
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发表时间：
2005-02-01
影响因子：
5.3
通讯作者：
Whittemore, SR
中科院分区：
文献类型：
--
作者：
Cao, QL;Zhang, YP;Whittemore, SR
使用Infinite Horizons（IH）撞击器在成年大鼠脊髓中创建分级挫伤性脊髓损伤（SCI），以研究损伤严重程度与解剖学、行为学和电生理结果之间的相关性。将成年Fisher大鼠等分为5组，分别在第9胸椎水平（T9）用100、125、150、175或200 kdyn冲击力造成挫伤。伤后4周每周进行经颅磁运动诱发电位（tcMMEPs）和131313开放视野运动分析。我们的研究结果表明，后肢运动功能下降，按照增加的损伤严重程度。运动缺陷与腹侧和外侧白色物质（WM）的损伤量成正比。运动功能与备用WM的量密切相关，其中包含网状脊髓束和本体脊髓束。对照组、100 kdyn组和125 kdyn组的tcMMEP潜伏期均正常。延迟潜伏期反应记录在一些125 kdyn损伤和所有的150 kdyn损伤的动物。在175和200 kdyn损伤的动物中没有记录到tcMMEP反应。比较tcMMEP反应与WM损失或脱髓鞘的区域确定了内侧腹外侧索（VLF）作为tcMMEP通路的位置。免疫组化和电镜（EM）分析显示，在损伤后28天的损伤腔周围的WM束脱髓鞘轴突的存在。这些数据支持了这样的观点，即腹侧和侧索中广泛的WM损伤可能是SCI后运动缺陷和缺乏tcMMEP反应的主要原因。(C)2004年爱思唯尔公司All rights reserved.
A graded contusion spinal cord injury (SCI) was created in the adult rat spinal cord using the Infinite Horizons (IH) impactor to study the correlation between injury severity and anatomical, behavioral, and clectrophysiological outcomes. Adult Fisher rats were equally divided into five groups and received contusion injuries at the ninth thoracic level (T9) with 100, 125, 150, 175, or 200 kdyn impact forces, respectively. Transcranial magnetic motor-evoked potentials (tcMMEPs) and 131313 open-field locomotor analyses were performed weekly for 4 weeks postinjury. Our results demonstrated that hindlimb locomotor function decreased in accordance with an increase in injury severity. The locomotor deficits were proportional to the amount of damage to the ventral and lateral white matter (WM). Locomotor function was strongly correlated to the amount of spared WM, which contains the reticulospinal and propriospinal tracts. Normal tcMMEP latencies were recorded in control, all of 100-kdyn-injured and half of 125-kdyn-injured animals. Delayed latency responses were recorded in some of 125-kdyn-injured and all of 150-kdyn-injured animals. No tcMMEP responses were recorded in 175- and 200-kdyn-injured animals. Comparison of tcMMEP responses with areas of WM loss or demyelination identified the medial ventrolateral funiculus (VLF) as the location of the tcMMEP pathway. Immunohistochemical and electromicroscopic (EM) analyses showed the presence of demyelinated axons in WM tracts surrounding the lesion cavities at 28 days postinjury. These data support the notion that widespread WM damage in the ventral and lateral funiculi may be a major cause for locomotor deficits and lack of tcMMEP responses after SCI. (C) 2004 Elsevier Inc. All rights reserved.