血管性痴呆大鼠学习记忆功能与脑电活动的长时程变化

目的观察血管性痴呆（VD）大鼠长时期学习记忆功能和脑电活动的动态变化规律。方法60只大鼠随机分为假手术组、模型7d组、模型15d组、模型1m组、模型2m组和模型4m组,每组10只。观察各组大鼠Morris水迷宫逃逸潜伏期（EL）的变化及脑电图（EEG）的频率、波幅及功率谱的改变情况。结果①各组大鼠随水迷宫测试次数的增加,逃逸潜伏期（EL）均逐渐缩短。与假手术组相比,各模型组EL均明显延长（P〈0.01）;模型各组间比较,除2m组和4m组差异不显著外（P〉0.05）,其余各组间均存在显著性差异（P〈0.05）。②假手术组大鼠EEG主要表现为8-10Hz的α波和4-7Hz的θ波,波幅较高。各模型组以θ波居多,δ波也增多,与假手术组相比,频率减慢（P〈0.05）,波幅也明显降低。功率谱分析表明假手术组的频率分配主要以α和θ为主,功率主峰在θ频段,能量分布集中,而各痴呆组频率分配主要以θ和δ为主,功率主峰在δ频段,能量分布分散。结论血管性痴呆发生和发展中脑电活动持续受抑制,脑功能异常,引起学习记忆能力降低。

Long Term Changes of Learning and Memory Ability and Electroencephalographic Activities in Vascular Dementia Rats

Objective To observe the long-term dynamic changes of learning and memory ability and electroencephalographic activities in vascular dementia（VD） rats.Methods VD rat models were established.Sixty rats were randomly divided into the sham-operated group（SO）,7-day VD model group（7dM）,15-day VD model group（15dM）,1-month VD model group（1mM）,2-month VD model group（2mM） and 4-month VD model group（4mM）.Escape Latency（EL） of rats tested in Morris Water Maze and Frequencies,amplitudes and power spectra of EEG were observed.Results ①EL became shortened following the increases of times of Water Maze training.There was a significant difference of EL between the SO and each model group（P〈0.01）;EL of each model group was much longer than that of SO group（P〈0.01）.But the difference of EL was inconspicuous between 2mM and 4mM groups（P〉0.05）.②The dominant rhythm of EEG was θ wave with the frequency of 4～7Hz and α wave of 8～10Hz in SO group,and the amplitude was relatively high.However,the dominant frequencies of model groups were mainly θ rhythm with increased δ rhythm.The frequencies of all the model groups were much slower than that of SO group（P〈0.05） and the amplitudes dampened.EEG power spectral analysis indicated that the power of EEG fluctuation in SO group mainly distributed in the sections of θ and α rhythms,and the peak of energy was concentrated on wave θ frequency section.While the power of EEG in each model group was mainly located in wave δ and θ sections and the energy was widely dispersed.Conclusion The depressed electroencephalographic activities and learning and memory ability damages were revealed and existed for a long time during the onset and development of VD.