D-半乳糖致认知障碍整体及离体模型的建立和评估

目的 通过构建D-半乳糖［D-（+）galactose，D-gal］致认知障碍的整体及离体模型，并检测两种模型的相关指标，探索两种模型的建立方法，并评估联合应用D-gal整体及离体模型的应用价值和前景。方法 采用连续腹腔注射D-gal生理盐水溶液8周制备D-gal致认知障碍整体动物模型，并采用Morris水迷宫评价小鼠的学习和记忆功能，之后检测脑组织中相关的分子指标评估模型效果；采用外源性给予体外培养的幼鼠海马区神经元细胞D-gal制备D-gal细胞模型，并检测细胞损伤的相关分子指标，评估离体模型效果和应用价值。结果 在D-gal模型下的Morris水迷宫实验结果显示，模型组动物的学习和记忆功能显著低于对照组动物，与此同时，模型组动物的神经元凋亡和氧化应激水平明显高于对照组动物；D-gal海马区神经元细胞模型中显示，随着D-gal剂量的增加，神经元细胞出现功能和形态学改变，其凋亡和氧化应激水平明显高于对照组神经元细胞。结论 D-gal致认知障碍整体模型及在离体状态下给予海马区神经元细胞D-gal均可以诱发细胞凋亡和氧化应激损伤，并导致动物学习和记忆功能下降；联合应用D-gal致认知障碍整体及离体模型可以成为今后研究认知障碍机制和药效学评价的有效模型之一。

Establishment and evaluation of in vivo and in vitro D-galactose induced cognitive impairment models

Objective To construct and explore the in vivo and in vitro D-galactose induced cognitive impairment models and evaluate the application value of the combined models in the study of cognitive impairments. Methods The cognitive impairment mice model induced by D-gal was prepared by continuous intraperitoneal injection of D-gal saline solution for 8 weeks, followed by detection of learning and memory functions with Morris water maze. The related molecular markers in the brain tissue were assayed to evaluate the effect and application value. D-gal cell model was prepared by adding D-gal in different concentrations into the cell cultural medium of neurons harvested from the hippocampus of young mice. The effect and application value were evaluated by detecting the molecular markers related to the level of cell injury. Results The Morris water maze on the D-gal model showed that the learning and memory functions of mice in the model group were significantly lower than those in the control group. Meanwhile, the levels of apoptosis and oxidative stress in the model group were significantly higher than those in the control group. In the hippocampal neuron model of D-gal, the neurons showed a dose-dependent morphologic and functional change with the increase of D-gal dose and the levels of apoptosis and oxidative stress were significantly higher than those in the negative control. Conclusion D-galactose can be successfully used to induce cognitive impairment models both in vivo and in vitro through the decrease of the learning and memory functions of mice and induction of apoptosis and oxidative stress in neurons. Combined application of the two models of D-gal can be one of effective and promising tools for the study of cognitive impairment and pharmacodynamic evaluation.