糖尿病小鼠学习记忆能力减退与海马锥体细胞树突棘变化的相关性

目的探讨代谢异常导致的海马区树突棘变化与认知功能障碍的关系。方法通过水迷宫实验检测动物学习记忆变化,通过Gol-gi-Cox染色结合体视学半定量技术分析海马CA1区锥体细胞树突棘密度变化。结果 2型糖尿病(T2DM)小鼠在一个月出现胰岛素抵抗,并伴随持续的高血糖及高胆固醇血症。2个月出现学习记忆能力下降(P<0.05),随时间延长而加重,4个月后海马CA1区锥体细胞树突棘密度显著下降(P<0.01)。结论研究结果表明T2DM持续高血糖,高血脂可能直接导致海马区神经细胞树突棘丢失,突触可塑性下降,从而出现认知功能障碍。

Diabetes mellitus induced impairment of memory associated with the changes of dendritical spine of pyramid cell in hippocampus

Objective To explore the roles of dendritical spine of pyramid cell in hippocampus on impairment of cognition under the condition of untreated-diabetes mellitus.Methods Learning and memory were tested by Morris water maze,and dendritical spines were observed by Golgi-Cox-staining.Stereological methods were used to quantitate the density of dendritical spine.Results The diabetic mice presented the insensitivity of insulin in fast at one month,accompanied the last hyperglycemia and hyperlipidemia.Diabetes caused the decline of cognition at two or four months in diabetic mice(P< 0.05).Density of dendritical spine of hippocampus was significantly decreased in diabetic mice compared with that of control group(P< 0.01).Conclusions Persistent high glucose and cholesterol in diabetic mice can lead to the lose of dendritical spine of hippocampus and the decreasing of synaptic plasticity,which can result in the impairment of memory.