亚急性衰老模型大鼠脑海马显微结构的变化

目的观察D-半乳糖制备的亚急性衰老模型大鼠脑海马显微结构的变化。方法选用3—4月龄Wistar大鼠18只，在适应性饲养1周后，随机分为对照组和模型组，模型组腹腔注射1％D-半乳糖50mg／kg·d，对照组腹腔注射等量生理盐水，连续6周。随后进行大鼠水迷宫实验，实验后取大鼠脑海马组织，进行光镜和电镜检查。结果模型组与对照组比较：大鼠水迷宫实验平均潜伏时间显著延长（P〈0．01）；游泳轨迹类型发生明显变化（P〈0．01）。光镜下模型组海马轮廓模糊，神经元细胞减少；海马CA3区可见到大量肿胀变性的神经元细胞，且分支明显减少，核仁浓缩变小，分叶不清，部分断离，细胞间排列松散，界限模糊；电镜下模型组海马CA3区神经元细胞胞浆水肿，浆内细胞器稀少，线粒体肿胀，脊突消失，呈气球样变，细胞核变小，核膜皱缩，核孔消失，核仁深染且边缘化，突触数量减少，间隙变大。结论D-半乳糖制备的亚急性衰老模型大鼠脑海马神经显微结构发生类似衰老的变化。

Subacute Aging Mode Rat Hippocampal Changes in The Microstructure

Objective To observe the changes of hippocampal micro-structure in subacut aging rats established by D- galactose. Methods Eighteen wistar rats which were 3-4 moon＇s age were adjustably bred for 1 week,the rats were divided into 2 groups：blank group and model group.The model group was set up by injected with 1% D-galactose 50mg/kg into abdominal cavity for 6 weeks,but blank one with saline.Then the rats were tested by morrise water maze .The hippocampal tissues were taken out from the rats after experiment,observing the hippocampal micro-structure through light micro- scope and electron microscope. Results Comparing with the blank group, in the experiment of mortise water maze,the average latent period of the model group extended distinctly （P〈0.01）;the types of swimming track of the model group changed remarkablely （P〈0.01）;Under Light microscope,the model group was been seen fuzzy outline of the hippocampus, neurons reduced;hippocampal CA3 area,we were seen a lot of swelling and degeneration of neurons,which decreased branch,the nucleolus enrichment smaller,sub-leaf unclear,in part from the broken cells,arrangement between loose and muddled;Under electron microscope,the model group CA3 neurons in the hippocampus cells edema,with plasma cell rare, mitochondrial swelling,sudden disappearance of ridge,was a balloon-like change,smaller nuclei,nuclear membrane shrinkage,nuclear hole disappeared,nucleolar Deep stained and marginalization,reducing the number of synapse,the gap larger. Conclusion D-galactose can induce the changes of hippocampal micro-structure ,wich similar to the changes of aging.