摘要
目的 :从形态学角度探讨新生鼠脑外伤后神经元变性的机理。方法 :建立新生 7d大鼠顶叶皮质脑挫伤动物模型 ,在脑外伤后 2h、6h、2 4h对同侧顶叶皮质和海马神经细胞进行电镜观察。结果 :神经元有两类改变 :( 1 )神经元树突和胞体呈巨大膨胀。早期内质网池扩大 ,线粒体致密和浓缩 ;此后内质网空泡化 ,线粒体进行性肿胀和空泡化 ,多聚核糖体从粗面内质网上解离 ,并散在于胞浆。核的改变出现于胞浆改变明显之后。核染色质由簇状集聚于核膜下呈钟面排列到向中央积聚成轮廓不规则的团块。轴突基本正常。 ( 2 )胞浆和胞核均浓缩 ,胞浆中有大小不等的空泡。结论 :内源性兴奋毒对未成熟脑创伤性神经元变性起十分重要的作用。
Objective: To explore the mechanism of the trauma-induced neurodegeneration in the newborn rat brain with the morphological method. Methods: Seven-day-old rat pups were subjected to concussive trauma on the parietal cortex and were killed 2 h, 6 h and 24 h later for ultramicroscopic observation on the ipsilateral parietal cortex and hippocampal neurons. Results: There were 2 type changes of neurons under electron microscope. The first change was massive swelling of neuronal dendrites and cell bodies accompanied with changes in cytoplasmic organelles such as dilation of the cistern of endoplasmic reticulum, condensation and shrinkage of mitochondria. Then endoplasmic reticulum became vacuous, mitochondria became progressively edematous, swollen and vacuous. The rough endoplasmic reticulum disintegrated with polyribosomes becoming disaggregated and ribosomal particles becoming scattered throughout the cytoplasm. Nuclear changes didnot occur until the cytoplasmic changes were already taken place. The nuclear chromation changesd beginning with the fomation of small clumps of chromatin migrating first to the nuclear envelope to form a clock-face profile, finally coalescing into central chromatin masses with irregular contour. The axonal processes didnot show pathologic changes. The second change of neurons was condensation of both the cytoplasm and nucleus with vacuoles in cytoplasm. Conclusion: Excitotoxic may be an important mechanism for trauma-induced neurodegeneration in immature brain.
出处
《解剖学杂志》
CAS
CSCD
北大核心
2004年第2期135-138,共4页
Chinese Journal of Anatomy
基金
上海市高教科技发展基金 (2 0 0 0B0 3)
