双侧前额叶中度损伤大鼠执行控制和空间学习与记忆功能的研究

A study on executive control and spatial learning/memory function after bilateral prefrontal lobe moderate injury in rats

目的:通过控制性皮质撞击法,制作双侧前额叶中度损伤模型并观察其对大鼠的执行控制功能和空间学习与记忆功能的影响。方法:40只雄性SD大鼠随机分成3组:正常对照组(n=10)、假手术组(n=10)、控制性皮质撞击(CCI)组(n=20)。CCI组大鼠应用控制性皮质撞击法制作双侧额叶打击颅脑创伤模型,其中打击速度:3.5m/s,打击深度:1.5mm,停留时间:400ms。于CCI后第4周末及第8周末分别进行GO/NO GO任务测试及水迷宫测试。结果:造模前各组各测试均无显著差异。造模后第4周CCI组GO/NO GO任务测试可见正确率显著下降(P<0.01),造模后第8周,各组的正确率下降和造模前比均有显著性差异(P<0.05)。造模后定位航行实验可见各组潜伏期均有下降,对照组和假手术组下降有显著性差异(P<0.05),但CCI组无显著性差异;第4、8周,与对照组相比,CCI组则均有显著性差异(P<0.01)。造模后第4周空间探索实验可见,对照组和假手术组与造模前相比无显著性差异(P>0.05),CCI组则有显著下降(P<0.01);造模后第8周,假手术组和CCI组与造模前相比差异有显著性意义(P>0.05),CCI组则与第4周相比也有显著差异(P<0.01)。结论:应用CCI方法进行双侧前额叶撞击制备大鼠中度颅脑创伤模型,可以造成大鼠执行控制能力的显著下降,并对大鼠的空间学习和记忆能力均有严重影响。在伤后一定时间内,执行控制能力可能会有部分的自然恢复,但空间学习和记忆能力损害则可能进行性加重。

To investigate the changes of executive control function and spatial learning/memory function after moderate traumatic brain injury （TBI） induced by controlled cortical impact （CCI） in bilateral prefrontal lobe. Method： Forty male SD rats were randomly divided into three groups： control group （n=10）, sham group （n= 10）, CCI group （n=20）. CCI was used to make the bilateral frontal lobe injury model （depth： 1.5mm, veloci- ty： 3.5m/s, dwell time： 400ms）. GO/NO GO tasks test and Morris water maze test were measured at 4 and 8 weeks after CCI. Result： Before modeling the test showed no significant difference in three groups. In the 4th week after model- ing the accuracy of GO/NO GO test decreased significantly（P〈 0.01）, but in the 8th week after modeling allgroups decreased had significant difference compared to the initial. In navigation test the escape latency in of each group decreased, the control group and sham group decreased significantly （P〈 0.05）, but not in CCI group; In the 4th and 8th week, CCI group had significantly difference compared with the control group（P〈 0.01）. Compared with before CCI, in the 4th week after CCI space exploration experiment showed no signifi- cant difference （P〉0.05） in control group and sham group, CCI group decreased significantly（P〈0.01）;in the 8 weeks after CCI, sham group and CCI group had significant difference （P〉 0.05） compared with before CCI, and CCI group had significant difference （P〈 0.01） in the 4th week after CCI. Conclusion： Bilateral frontal lobe moderate TBI caused by CCI could declined the executive control function significantly and affected spatial learning/memory function seriously. Within a certain time after CCI, executive control function mightbe have natural recovery partly, but the spatial learning and memory mightbe have aggra- vated damages.