中文摘要：

目的 观察不同海拔高度对大鼠低压缺氧脑损伤的空间记忆的影响及脑组织病理改变.方法 120只Wistar 大鼠,分为模拟海拔4000 m（n =30）、6000 m（n =30）、8000 m（n =30）及平原组（海拔500 m,n=30）,利用低压低氧动物实验舱模拟相应海拔高度,各组大鼠分别在各自模拟海拔高度舱内连续饲养3d,观察大鼠生存状态;3d后从舱内取出大鼠,各组随机抽取8只大鼠,在舱外利用Morris水迷宫图像自动采集处理系统,对大鼠进行寻找隐藏平台的平均逃避潜伏期（MEL）测试;同时,各组从剩余大鼠中随机抽取8只,从舱内取出后立即处死,断头取脑,采用干/湿比重法测定各组大鼠脑组织含水量的变化;采用苏木精-伊红染色法（HE）观察各组大鼠脑组织病理变化.结果 Morris水迷宫实验中,各模拟高原组MEL较平原组增加;不同高原组间比较,随海拔升高,MEL延长,差异显著（P＜0.01）.各模拟高原组大鼠脑组织含水量均较平原组显著增加（P＜0.05）,各高原组间比较,随海拔升高,脑组织含水量逐步上升,差异明显（P＜0.05）;各高原缺氧组大鼠脑组织病理切片可见胶质细胞和周围血管水肿,且随海拔升高,水肿程度加重.结论 高原低压缺氧环境可导致大鼠脑水肿,进而造成大鼠学习记忆功能障碍.

英文摘要：

Objective To observe the influence of simulated different high altitude anoxia on rat＇s space memory under low pressure and anoxia condition as well as the pathologic change of brain tissue. Methods 120 Wistar rats were randomly divided into 4 groups： 4000 m group（n =30） ,6000 m group（n =30） ,8000 m group（n = 30） and plain group（n =30）. The rats in each of the first 3 groups were fed in the stimulated chambers of their fixed altitude for 3 days,while the rats in plain group were fed outside the chamber. 8 rats were selected from each group and the mean escape latency（MEL） for the invisible platforms in Morris water maze automatic image collection system was recorded. Other 8 rats in each of the group fed in the chamber, as soon as they were taken out of the chamber,were killed as well as other 8 rats in plain group. Their brain tissues were taken out and the changes of water content were detected by dry weight method. HE stain method was applied to observe the pathological changes of the brain tissue. Results The Morris water maze analysis showed that the MEL in the 3 stimulated groups was longer than that in plain group （P 〈 0.05） ;MEL got longer with the increase of altitude and the difference among the 3 stimulated groups was obvious （P 〈 0.05 ）. The same change of water content of the brain tissues was observed among the 3 stimulated groups （P 〈 0.05 ）as MEL. Glial cells and peripheral vascular edema got worse with the increase of the altitude. Conclusions Low pressure and anoxia at high altitude may lead to brain edema of the rats and result in learning and memory block.