大鼠纹状体边缘区与海马学习记忆功能的行为学比较研究

目的 探讨MrD与海马这两个不同脑区在大脑学习记忆功能上的区别和作用地位。方法 在Y迷宫训练大鼠后即刻或24h后化学损毁大鼠双侧MrD或切断双侧穹窿海马伞(fornix/fimbria，FF)，训练后6d再观察化学损毁双侧MrD组、MrD对照组、切断双侧FF组和FF对照组大鼠在Y迷宫中学习记忆的行为表现；或在化学损毁大鼠双侧MrD或切断双侧FF下后7d，在Morris水迷宫中检测上述各组的学习记忆能力。结果 在Y迷宫测试的正确反应次数方面，训练后即刻或24h后损毁双侧MrD组与MrD对照组比较均明显减少；训练后即刻切断双侧FF组与FF对照组比较也明显减少，但训练24h后切断双侧FF组与FF对照组比较则无显著意义的差别。在Morris水迷宫试验中，损毁双侧MrD组和切断双侧FF组与各自的对照组比较，平均逃避潜伏期延长，穿环次数减少，但两者之间则无显著意义的差别。结论 MrD与海马均与大鼠的空间学习记忆功能有密切关系；但在Y迷宫逃避性学习方面，海马仅参与陈述性记忆的早期阶段，而MrD则与早、晚两个阶段均有关。提示MrD和海马在学习记忆功能方面可能不同，MrD可能涉及更复杂的记忆过程。

Comparative studies on the learning and memory function between the hippocampus and the marginal division of the neostriatum in rat by Y-maze and Morris water maze tests

Objective The differential contributes of the hippocampus and the marginal division of the neostriatum (MrD) to learning and memory function of the brain were investigated. Methods In Y-maze test groups, Chemically destroyed bilateral MrD or transected bilateral fornix/fimbria (FF) were performed in the rat brains immediately or 24 h following the acquisition of the avoidance learning task. The rats' performance on the task was investigated again 6 days after acquisition. In the Morris water maze test groups, the learning and memory abilities of rats with the MrD or the FF lesions were measured 7 days after lesion. Result On condition of immediate lesion after acquisition , the correct run times of the Y-maze test in both the MrD lesioned and the FF cutted groups were depressed significantly than those in the control groups, but on condition of the lesion 24 h following the acquisition , only in the MrD lesioned group the parameter was depressed significantly. In the Morris water maze test, the average escape latencies and cross times of both the MrD lesioned and the FF cutted groups were obviously lower than those of the both control groups, but there were no differences in the two parameters between the the MrD lesioned and the FF cutted off groups. Conclusion It is indicated that hippocampus contributed to spatial memory, but only was involved in the early consolidation of memory for the footshock avoiding response. In contrast, the MrD contributed to both early and late consolidation of the memory and spatial memory. It seems that MrD and hippocampus may play different roles in the mechanism of learning and memory in the brain , and the MrD is probably involved in more complicated memory procedures than the hippocampus is.