Neuronal survival and glial reactions after recurrent laryngeal nerve resection in the rat
Neuronal survival and glial reactions after recurrent laryngeal nerve resection in the rat
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DOI：
10.1097/01.mlg.0000161362.43320.b2
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发表时间：
2005-04-01
期刊：
影响因子：
2.6
通讯作者：
Mattsson, P
中科院分区：
文献类型：
--
作者：
Hydman, J;Svensson, M;Mattsson, P
目的/假设：喉返神经（RLN）的完全性轴索损伤导致喉内肌协调功能的永久性丧失。本研究的目的是研究RLN远端切除后模棱两可核的逆行反应、神经元存活和胶质反应，以评估对神经保护物质的潜在需求。研究设计与方法：选取31只成年大鼠，切除左RLN一段。在病变后2 ~ 28天处死动物前，用氟金逆行追踪模棱两可核运动神经元。分离脑干进行神经元定量和免疫组织化学分析。在连续切片上对歧义核进行神经元计数。应用免疫组织化学方法研究了歧义核的神经胶质反应。结果：损伤后1个月内，歧义核内运动神经元数量未见明显减少。星形胶质细胞和小胶质细胞在损伤后7 ~ 14天表现出免疫反应性增强，随后胶质细胞反应略有下降。在研究期间，小胶质细胞未显示转化为巨噬细胞的迹象，进一步表明没有神经元损失。结论：成年大鼠切除RLN后病变后1个月内不会发生神经元死亡，因此神经保护物质在RLN损伤后的作用不大。神经胶质反应的出现方式与其他周围神经病变后类似，但不会引起神经元损失。
Objectives/Hypothesis: Complete axonal injury to the recurrent laryngeal nerve (RLN) leads to permanent loss of coordinated function of the intrinsic muscles of the larynx. The aim of the present study was to investigate retrograde reactions, neuronal survival, and glial reactions in the nucleus ambiguus after a distal resection of the RLN to evaluate the potential need for neuroprotective substances. Study Design and Methods: A segment of the left RLN was resected in 31 adult rats. Before sacrifice of the animals at 2 to 28 days postlesion, the motor neurons in the nucleus ambiguus were retrogradely traced by the use of Fluorogold. Brainstems were isolated and processed for neuron quantification and immunohistochemical analysis. Neuron counts were performed in the nucleus ambiguus on serial sections. Glial reactions were investigated in the nucleus ambiguus using immunohistochemistry. Results: No decrease in the number of motor neurons in the nucleus ambiguus could be demonstrated up to 1 month postlesion. Astroglia and microglia showed increased immunoreactivity at 7 to 14 days postinjury, followed by a slight decline in glial reaction. Microglia revealed no signs of transformation into macrophages during the study period, further indicating the absence of neuronal loss. Conclusions: Neuronal death does not occur within 1 month postlesion as a result of resection of the RLN in the adult rat, and neuroprotective substances should therefore be of minor value after RLN injury. Glial reactions appear in a similar fashion as after other peripheral nerve lesions not causing neuronal loss.