大鼠空间辨别性学习记忆的脑fMRI研究

FMRI Study of Rat Brain during Spatial Learning and Memory

目的 运用功能性核磁共振 (fMRI)技术 ,探讨已建立空间辨别性学习记忆的模型大鼠脑中代表记忆痕的高兴奋区 .方法 通过水迷宫建立大鼠空间辨别性学习记忆模型 ,对不同训练时间段的模型组与游水组和对照组大鼠行fMRI检查大鼠脑中高兴奋区 .结果 模型大鼠脑内 ,与学习记忆相关的脑区额叶、颞叶等神经元活动增强 ,表现为高兴奋区 .该兴奋区有时空差异 .在训练 7天时 ,脑内高兴奋区位于前额叶皮质和嗅球 ,兴奋度高 (象素水平p <0 .0 0 0 1) .在 14天时 ,脑内高兴奋区仍位于前额叶 ,兴奋度亦高 ,但较前稍低 (p <0 .0 0 0 5 ) .在 2 1天时 ,脑内高兴奋区位于颞叶皮质 ,兴奋度高 (p <0 .0 0 0 1) .游水组和对照组无高兴奋区 (p >0 .0 0 1) .结论 已建立空间辨别性学习记忆的大鼠脑内出现代表记忆痕的高兴奋区 .在训练不同时间段 ,脑内高兴奋区的强度和部位发生相应的变化 .此变化提示前额叶皮质是短期记忆过程中重要的整合中枢 。

Objective To study the cerebral high-excitive regions representing memory trace during spatial learning and memory by use of fMRI. Methods Model groups established spatial learning and memory by Morris water labyrith training. Model groups ,swimming control and blank control group were examined with fMRI to observe cerebral high-excitive region. Results The cerebral high-excitive regions in model rats were frontal and temporal lobe relatived with learning and memory. High- regions in the brain were different in different time-phase of training. Excitivity was higher in the prefrontal lobe and the olfactory bulb in 7-day (limited level p<0.0001) than in the prefrontal lobe in 14-day (p<0.0005). Excitivity was also higher in the temporal lobe in 21-day (p<0.0001). Cerebral high-excitive regions did not be observed in swimming control and blank control groups (p>0.001). Conclusions There are exist the cerebral high-excitive regions representing brain memory trace during spatial learning and memory by use of fMRI. This excitive intensity and location are changed in the defferent time-phase of training. It suggests prefrontal lobe is important integrative nerve center and temporal lobe participate in long-time memory.