衰老过程中小鼠学习记忆与脑内突触结构参数变化的相关性

用Y-迷宫和一次性被动回避反应模型，对不同月龄小鼠的学习记忆行为进行了动态观察，同时定量分析了青年、中年和老年小鼠海马CA3区和皮层感觉运动区的突触结构参数。结果表明，随着月龄的增长，观察到以下变化：（1）分辨学习及记忆保持力显著下降；（2）两脑区突触界面曲率和间隙宽度加大和变宽，突触后致密物质变薄。此外，穿孔性突触和三种弯曲型突触比例也有不同程度的变化。结果提示，衰老过程中，小鼠学习记忆行为与其脑内突触结构参数变化密切相关。

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

In this study, the abilities of spontaneous behavior, learning and memory of mice during natural aging were investigat ed using one-trial passive avoidance task and Y-maze. The synaptic structural parameters were quantitatively analysed mainly in two cerebral areas (hippocampal CA3 and sensori-motor areas of cerebral cortex) in three groups (young, mid-age and old). The main results are as follows: (1) The abilities of discrimination learning and memory retention was decreased significantly. (2)The curvature of synaptic interface and width of synaptic cleft were remarkably increased, while the thickness of postsynaptic density (PSD) was reduced. In the meantime, the occurrence of perforated synapse and percentage of different types of synaptic curvature were also changed in the two brain areas mentioned above. These results suggest that the alterations of learning and memory behavior are closely associated with that of synaptic structural parameters of brain in natural aging mice.