弥漫性轴突损伤胆碱能纤维改变的实验研究

目的通过大鼠弥漫性脑损伤模型观察海马及乳头体内的轴突损伤,了解轴突损伤后上述结构中胆碱酯酶纤维的变化,探讨轴突损伤与伤后记忆功能障碍的相关性.方法用Marmarou介绍的落体打击装置致伤动物,对海马和乳头体区脑组织进行胆碱酯酶(AChE)纤维染色.结果该模型较好地模拟了轴突损伤的表现,简便实用.在这个模型中轴突损伤的最常见部位为桥脑基底部和小脑上脚,其次为大脑半球白质、海马和乳头体.海马结构内含有大量胆碱酯酶阳性染色纤维.与对照组相比中,损伤10天海马CA1区,CA3区,齿状回分子层和乳头体内纤维密度明显低于对照组大鼠(P＜0.01).结论大鼠损伤后海马区和乳头体内胆碱酯酶阳性纤维明显减少,这可能是弥漫性轴突损伤病人记忆功能损害的原因.

Experimental study on the changes of cholinergic fibers in diffuse axonal injury

Objective To observe the axonal injury and the changes of cholinergic fibers after axonal injury in hippocampus and corpus mamillare, and to find out its correlation with memory loss through the diffuse brain damage in rats. Methods The head injured animal model was impacted by an weight drop device designed by Marmarou. The samples of each rat brain were taken to do the acetylcholinesterase (AChE) containing fiber staining and were examined under light microscopy. Results The animal model fairly simulated diffuse axonal injury(DAI) in human being. The most common site of DAI in this experiment was the basal portion of the pons and superior cerebellar peduncle. The second was the cerebral white matter, hipocampus and corpus mamillare. There were plenty of AChE positive fiber in hippocampus and corpus mamillare. Compared with the control group, 10 days after injury, the density of AChE positive fibers in CA1, CA3, and dentate gyrus of hippocampus and corpus mamillare was significantly lower than that in controls (P<0 01). Conclusions The AChE positive fiber significantly decreased in rat hippocampus and corpus mamillare in diffuse axonal injury, which may be the cause of memory loss in the patients of diffuse axonal injury.