外伤性嗅觉障碍大鼠嗅黏膜的组织学变化  

Histological changes of olfactory epithelium in rats with traumatic anosmia

作　　者：苗旭涛[1] 魏永祥[1] 张聪[1] 王向东[1] 范尔钟[1] 羡慕[1] 赵兰峰[2] 韩德民[1] 

机构地区：[1]首都医科大学附属北京同仁医院耳鼻咽喉头颈外科北京市耳鼻咽喉科研究所,北京100730 [2]首都医科大学神经生物学教研室,北京100069

出　　处：《中国耳鼻咽喉头颈外科》2007年第1期57-61,共5页Chinese Archives of Otolaryngology-Head and Neck Surgery

基　　金：北京市自然科学基金资助项目(7042012)

摘　　要：目的构建大鼠外伤性嗅觉障碍模型,观察不同时间点嗅黏膜组织学变化。方法神经切断组(40只)和对照组(20只)大鼠均在显微镜下暴露左侧嗅球,沿筛板切断神经组切断大鼠左侧嗅神经。采用嗅觉诱发电位(olfactoryevokedpotentials,OEPs)和神经示踪验证造模效果。术后1天、5天、2周、3周、6周处理大鼠,处理前1天每组各取2只大鼠经鼻腔滴注辣根过氧化物酶(horseradishperoxidase,HRP)。嗅黏膜及嗅球冰冻切片后观察嗅上皮的厚度、细胞数量的变化以及嗅神经的连续性,并且行免疫组化观察嗅上皮中的新生嗅感觉神经元(olfactoryreceptorneurons,ORNs)。结果OEPs及神经示踪证实手术方法可以完全切断嗅神经。术后1天,切断侧黏膜中ORNs出现凋亡,两组大鼠双侧嗅上皮厚度和细胞数量比值无明显变化。5天时切断侧嗅上皮中细胞数量减少,上皮厚度变薄,嗅球中无HRP标记纤维。术后2、3周大鼠嗅球中出现蓝色标记,嗅上皮厚度和细胞数量逐渐增加,但仍然与对照组有差异,此时嗅上皮中出现大量的新生ORNs。经过6周的恢复,嗅上皮厚度及细胞数量基本恢复至对照组水平,嗅上皮中有较多的新生ORNs,其轴突与嗅球重新建立神经联系,但是上皮中仍然有一定数量的凋亡细胞。结论嗅神经切断术可以作为制作外伤性嗅觉障碍的可靠方法;由于ORNs具有再生能力,大鼠嗅神经切断后嗅黏膜在一定时间内基本恢复至正常水平。OBJECTIVE To establish an animal model of traumatic anosmia in rats and observe the histological changes of olfactory epithelium. METHODS The left olfactory bulbs of all rats （60） were exposed under microscope, while the olfactory nerve transection group （40） received the operation to transect the left olfactory nerve. Olfactory evoked potentials （OEPs） and neural tracing were used to evaluate the results of the operation in the preliminary experiment. One day before sacrifice, 2 animals of each group were anesthetized and received intranasal infusions of 30 % horseradish peroxidase （HRP）. On day 1, days 5, weeks 2, weeks 3 and weeks 6 after the operation, the rats of different groups were anaesthetized, then olfactory epithelium and bulb were taken out after transcardial perfusion with 1% paraformaldehydel 1.25 % glutaraldehyde. Horizontal sections were sliced for the histological examination including staining with hematoxylin ＆ eosin, immunohistochemistry, TUNEL, and tetramethy benzidine （TMB） to observe the changes of the olfactory epithelium and the regeneration of olfactory receptor neurons （ORNs）. RESULTS OEPs and neural tracing showed the olfactory nerve was severed with the olfactory nerve transection in the preliminary experiment. One day after the transection, there is no connection between the olfactory nerve and the olfactory bulb in the transected side. Five days later, the epithelium had a lot of apoptotic cells and the thickness decreased to the lowest value. Two or 3 weeks after the operation, the cell number and thickness of the olfactory epithelium increased gradually, there were some staining for HRP in the olfactory bulb, and more growth associated protein （Gap）-43 marked ORNs were visible in the transected side. After 6 weeks＇ recovery, both the thickness and cell number could reach the control level, and the connection between olfactory epithelium and olfactory bulb was re-established. CONCLUSION Olfactory nerve transection is a reliable method to establish t

关 键 词：创伤 神经系统 嗅觉障碍 嗅觉受体神经元 神经再生 

分 类 号：R765.8[医药卫生—耳鼻咽喉科]