小鼠的记忆与脑内突触结构参数变化的相关性

比较不同月龄小鼠学习记忆力与脑内突触结构参数变化的相关性。选用１月龄和６月龄小鼠，用Ｙ－迷宫检测分辨学习能力，用一次性被动回避反应检测记忆力。然后杀鼠取脑，进行超微结构观察和定量分析测定。结果表明：（１）１月龄小鼠的分辨学习能力优于６月龄小鼠，记忆力也有优于６月龄小鼠的趋势。（２）无论在海马或大脑皮层体区，有两种结构参数有一致性增龄变化，即６月龄小鼠突触界面曲率都比１月龄小鼠显著和极显著增大；而６月龄小鼠上述两脑区的突触后致密物质厚度都极显著地小于１月龄小鼠。实验结果提示，脑内突触界面结构的增龄性变化可能是学习记忆力增龄性变化的结构基础。

CORRELATION BETWEEN LEARNING-MEMORY AND THE CEREBRAL SYNAPTIC STRUCTURAL PARAMETERS IN MICE

This study investigated the correlation between learning-memory capacity of different month-aged mice and their central synaptic structural parameters.The discrimination learning capacity was tested by Y-maze and memory retention was observed by using one trial passive avoidance response in both 1-month and 6-month aged mice respectively.Then the animals were killed and the hippocampus and sensori-motor areas of the cerebral cortex were prepared for electron microscopy.The electron microphotographs were analysed quantitatively by XY-biological image analysis system.The main results were as follows:(1)The descrimination learning capacity of 1-month aged mice were significantly better than that of the 6-month aged mice(p<0.05),while memory retention of 1-month aged mice was slightly superior to that of the 6-month aged mice.(2)The curvatures of synaptic interface of 6-month aged mice were greater that of the 1-month aged mice(p<0.05 in the sensori-motor areas:p<0.01 in the hippocampus),while the PSDs of 6-month aged mice were less than that of the 1-month aged mice(p<0.01).These results suggested that changes of learning-memory capacity with increasing age may be based on the changes of the structure of synaptic interface in the brain of mice.