电镜下大鼠下牙槽神经压榨损伤后半月神经节神经元线粒体的超微结构观察

Morphological changes of mitochondria in trigeminal ganglion neurons following inferior alveolar nerve crush in rats

关键词:  线粒体  下牙槽神经  TG神经元  压榨损伤

Key words:  mitochondria  interior alveolar nerve  TG neurons  nerve crash

摘要:

目的　观察大鼠下牙槽神经损伤后半月神经节（TG）神经元线粒体的超微结构变化，探讨线粒体参与外周神经损伤及修复机制的结构基础。　方法　选取健康SD雄性大鼠10只，随机分为空白对照组2只，实验组8只，建立大鼠单侧下牙槽神经压榨损伤的动物模型，选取代表性时间点制备TG电镜样品，透射电镜下观察TG神经元细胞体及其轴突中线粒体的超微结构变化。　结果　电镜下，空白对照组及实验对照侧TG神经元细胞体及其轴突中均富含线粒体，线粒体双层膜结构清楚，嵴致密、排列整齐，罕见线粒体的肿胀或空泡样变性。实验组大鼠下牙槽神经压榨损伤24 h后，损伤侧TG神经元细胞体及其轴突中线粒体发生肿胀、嵴溶解等结构异常性变性。1周时，实验侧TG神经元、无髓鞘的C型及有髓鞘的A型轴突中均出现大量空泡样变性线粒体。　结论　下牙槽神经压榨损伤后，损伤的TG神经元线粒体会发生肿胀等结构变化。

Abstract:

Objective　To observe the dynamic ultrastructure of mitochondria in trigeminal ganglion (TG) neurons, which possibly involve in the mechanisms of peripheral nerve injury and repair induced by inferior alveolar nerve injury in rats.　Methods　Ten Sprague-Dawley female rats were randomly divided into control group and inferior alveolar nerve crush group. After nerve injury, the TG were dissected and prepared for observation with transmission electron microscopy at representative time points. The mitochondrial ultrastructure in TG neuronal cell bodies and their axons were observed.　Results 　At 24 h post inferior alveolar nerve crush, atypical mitochondria which appeared as swollen structures with both vacuoles and collapsed cristae were found. At 1 w after injury, a number of abnormal mitochondria that appeared as swollen structures with both large vacuoles and an accumulation of electron-dense material at one pole were observed in cells bodies, C-fibers and myelinated A-fibers.　Conclusions　The structural abnormalities as swollen could be found in mitochondria of TG.