天泰1号对自发阿尔茨海默病鼠海马CA1区分子层突触可塑性的影响超微结构定量研究

背景中枢神经的突触可塑性是行为依赖性学习记忆的核心基础,治疗阿尔茨海默病的天然中药是否通过增加突触可塑性来改善学习记忆尚罕见报道.目的观察天泰1号对自发阿尔茨海默病模型学习记忆功能及神经突触可塑性的影响.设计随机对照实验.单位深圳市中西医结合研究所.材料实验在深圳市中西医结合临床研究所二级动物实验室完成.实验动物为昆明种小鼠.方法从21个月龄昆明种小鼠筛选出自发阿尔茨海默病(记忆障碍)鼠52只,随机分为4组即老年痴呆组、西药对照组、天泰1号6.80 g/kg组、天泰1号20.41 g/kg组,另设13只老年学习记忆正常鼠为老年正常组.西药对照组给以甲磺酸二氢麦角碱0.6 mg/kg,天泰1号6.80 g/kg,20.41 g/kg组分别予天泰1号方6.80 g/kg及20.41 g/kg,以上均研配成0.5 mL液体灌胃给药,连续60 d,老年正常组和老年痴呆组均灌以等量双蒸水.用跳台实验检测学习记忆成绩;海马CA1区脑组织超薄切片,透射电镜观察,并全自动显微图像分析系统定量检测突触可塑性参数.主要观察指标①天泰1号不同剂量对自发阿尔茨海默病鼠学习记忆的影响.②突触电镜观察及体视学定量检测结果.结果实验过程中实验动物无脱失,均进入结果分析.①天泰1号不同剂量对自发阿尔茨海默病鼠学习记忆的影响天泰1号6.80 g/kg组,20.41 g/kg组的学习、记忆错误次数均小于老年痴呆组,且天泰1号20.41 g/kg组的学习、记忆错误次数小于天泰1号6.80 g/kg组;天泰1号6.80 g/kg组,20.41 g/kg组的学习训练逃避潜伏期小于老年痴呆组,记忆测试安全平台潜伏期大于老年痴呆组,且天泰1号20.41 g/kg组的记忆测试安全平台潜伏期大于天泰1号6.80 g/kg组.②突触电镜观察及体视学定量检测与老年正常鼠相比,老年痴呆鼠出现突触数明显减少,部分突触间隙模糊不清,突触连接间断,突触小泡大小不等等变性现象,其余各组也可见突触变性改变,但程度较模型组轻.天泰1号可明显增高其海马CA1区分子层突触的数密度和面密度,且天泰1号20.41 g/kg组所增高的幅度大于天泰1号6.80 g/kg组.结论天泰1号可明显改善自发阿尔茨海默病模型鼠的学习记忆障碍,这一作用可能与其促进突触再生,改善其大脑的突触可塑性有关,其作用呈现出一定的量效关系.

Influence of tiantai No. 1 recipe on synaptic plasticity of the hippocampal CA1 region of spontaneous Alzheimer disease models: Quantitative research of ultrastructure

BACKGROUND: The synaptic plasticity of central nerves is the key basis of behavior-dependent learning and memory, there have been few reports about weather the Chinese herbal medicine for treatment of Alzheimer disease is through enhancing synaptic plasticity to improve learning and memory.OBJECTIVE: To investigate the effect of tiantai No. 1 recipe on learning and memory function and synaptic plasticity of spontaneous Alzheimer disease models.DESIGN: A randomized and controlled trial.SETTING: Institute of Combination of Traditional Chinese Medicine and Western Medicine of Shenzhen.MATERIALS: The experiment was completed at the grade Ⅱ Laboratory of Institute of Combination of Traditional Chinese Medicine and Western Medicine of Shenzhen City. The experimental animals were mice of Kunming strain.METHODS: Totally 52 Kunming mice, aged 21 months, with spontaneous Alzheimer disease (memory impairment) were chosen, and at random divided into 4 groups: senile dementia, western drug control, tiantai No. 1recipe 6.80 g/kg and 20.41 g/kg groups; besides 13 mice with normal learning and memory power were chosen as normal senile group. Hydergine 0.6 mg/kg was given for mice in western drug control group, tiantai No. 1recipe 6.80 g/kg and 20.41 g/kg were respectively given for mice in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups. The medicines above were all prepared into 0.5 mL solution and given by gavage, for consecutive 60 days. The mice in normal senile and senile dementia groups were given double distilled water of the same volume. The learning memory power was tested by jumping stand; ultrathin cerebral section of hippocampal CA1 region was examined with transmission electron microscope,and some parameters of synaptic plasticity was also quantitatively detected with automatic micrographic analysis system.MAIN OUTCOME MEASURES: ① The effect of tiantai No. 1 recipe in different doses on learning and memory of spontaneous Alzheimer disease mice. ② Observation of synapse with electron microscope and quantitative examination stereologically.RESULTS: All animals involved in the trial entered the final result analysis without any loss. ① The effect of tiantai No. 1 recipe in different doses on learning and memory of spontaneous Alzheimer disease mice: The error numbers of learning and memory in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups were smaller than that in senile dementia group,and the error number of learning in tiantai No. 1 recipe 6.80 g/kg group was smaller than that in tiantai No. 1 recipe 20.41 g/kg group. The escape latent periods of learning training was smaller than that in senile dementia group and the safe platform latent periods of memory in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups were longer than that in senile dementia group, and the safe platform latent period of memory in tiantai No. 1 recipe 6.80 g/kg group was smaller than that in 20.41 g/kg group. ② Observation of synapse with electron microscope and quantitative examination stereologically: Compared with the mice in normal senile group, for mice in senile dementia group, there occurred degenerative phenomena: the number of synapses reduced, a part of synaptic clefts were not clear, the synaptic junction was interrupted, and he sizes of synaptic vesicles were different; in the rest groups there were also degenerative phenomena, however the degrees were milder than those in the model group. Tiantai No. 1 recipe could remarkably raise the number density and sectional density of synapses in the hippocampal CA1 region, and the increased extents in 20.41 g/kg tiantai No.1 recipe was larger than those in 6.80 g/kg tiantai No. 1 recipe.CONCLUSION: Tiantai No. 1 recipe can remarkably improve their learning and memory impairments, which may be related with that it promotes re-generation of synapse and improves the plasticity of cerebral synapses;and the action presented a relationship of dose-effect.