神经损伤对三叉神经中脑核神经元Trk受体表达的影响(英文)

EFFECTS OF NERVE INJURY ON THE EXPRESSION OF Trk RECEPTOR PROTEINS LOCALIZED ON THE TRIGEMINAL MESENCEPHALIC NEURONS

本研究应用免疫荧光结合逆行束路追踪技术观察了轴突切断对支配咬肌的三叉神经中脑核(Me5)神经元所含Trk受体蛋白,即TrkA、TrkB和TrkC表达的影响。通过大鼠咬肌神经给予荧光金,标记支配咬肌的Me5神经元;分别于切断咬肌神经后7和14 d对脑切片进行免疫组织化学染色并观察荧光金(FG)标记的Me5神经元表达的三种Trk受体。以双标记神经元占荧光金标记神经元总数的百分率为指标进行统计学分析,结果显示:(1)神经切断后7和14 d,TrkA免疫反应阳性神经元比例有显著性增加(P<0.05);(2)神经切断后随着存活时间的延长,TrkB免疫阳性神经元比例逐渐增加,但无显著性区别(P>0.05);(3)TrkC表达无显著性变化(P>0.05)。本研究结果提示,咬肌神经切断对三种Trk受体的表达有不同的影响,Trk受体表达的模式可能反应出Me5神经元对外周神经损伤后的一种适应。

Immunofluoresceuce histochemistry combined with retrograde tracing technique was employed to observe the effects of masseteric nerve transection on the expression of Trk （ tropomyosin-related kinase） receptor proteins, namely TrkA, TrkB and TrkC in the trigeminal mesencephalic nucleus （Me5） of the rat. At 7 and 14 days following transection of masseteric nerve through which Fluorogold （FG） was applied to identify the Me5 neurons innervating masscter, brain sections were immunohistochemieally processed to detect the three Trk isoforms in FG-labeled Me5 neurons. With the percentage of douhle-labeled neurons to the total number of FG-labeled neurons as the index, we demonstrated （ I ） a significant increase in the percentage of TrkA-immunoreactive （IR） Me5 neurons at both 7 and 14 days after nerve transection, （2） nn significant, but gradoal, increase in the percentage of TrkB-1R Me5 neruons with longer survival time post transection and （3） little change of TrkC expressioa. The current findings indicate that axotomy differently affected the expression of the individual Trk receptors and these expression patterns may reflect an adaptation of the Me5 neurons to the peripheral nerve injury.