慢性间断性低氧大鼠认知功能和脑胆碱能神经元的进行性变化

The progressive effects of chronic intermittent hypoxia on cognitive function and the cholinergic neuron in rats

目的:探讨慢性间断性低氧(CIH)大鼠认知功能的进行性变化及其与脑胆碱能神经元变化的关系。方法:成年雄性SD大鼠40只,随机均分为对照组、慢性间断性低氧1,3,5周组。应用Morris水迷宫检测认知功能的变化;利用HE染色在光镜下计数前额叶皮层和海马坏死神经元数;利用免疫组化方法检测前额叶皮层和海马胆碱乙酰转移酶(ChAT)阳性表达。结果:CIH各组大鼠学习记忆能力呈进行性下降趋势;与对照组比较,CIH5w组出现明显学习记忆功能障碍(P<0.05)。CIH各组前额叶皮层和海马变性坏死神经元数增多,且随低氧时间延长,上述改变呈慢性进行性加重趋势。CIH各组前额叶皮层和海马ChAT阳性表达逐渐下降;与对照组比较,CIH3w组和CIH5w组前额叶皮层和海马ChAT阳性表达明显减少,差异具有显著性(P<0.05)。结论:慢性间断性低氧大鼠认知功能进行性下降与前额叶皮层和海马神经元病理性损伤、ChAT表达进行性减少有关。

Objective：To investigate the relation between the progressive effects of chronic intermittent hypoxia（CIH） on cognitive function and the change of cholinergic neuron.Methods：Forty adult male Sprague-Dawley rats were randomly averagely divided into four groups：control group,CIH 1 week group,CIH 3 week group and CIH 5 week group.The cognitive function was assessed by the Morris Water Maze.The necrosis neurons in prefrontal cortex and hippocampus were observed and counted.The cholin acetyltransferase（ChAT） immunostained cells in prefrontal cortex and hippocampus were identified and quantitated.Results：The spatial learning and memory impairments progressed from 1 to 5weeks in rats.Compared with the control group,the cognitive impairments in CIH5w group were significant（P0.05）.The degeneration or necrosis neurons in prefrontal cortex and hippocampus were significantly increased in CIH rats,and worsen gradually along with the hypoxia.The ChAT immunostained cells in prefrontal cortex and hippocampus were gradually reduced.The ChAT immunostained cells of prefrontal cortex and hippocampus in CIH3w group and CIH5w group were less than that in control group（P0.05）.Conclusion：Chronic intermittent hypoxia induced slowly progressive spatial learning and memory impairments in rats,which maybe associated with the damage of neurons and the reduction of ChAT in prefrontal cortex and hippocampus.