GAD67-GFP精神分裂症小鼠行为学改变及海马齿状回颗粒细胞层GABA能神经元的表达

The change of behavior and expression of GABAergic neurons in hippocampal dentate gyrus granular cell layer of GAD67-GFP knock-in mouse with schizophrenia

目的:探讨谷氨酸脱羧酶67-绿色荧光蛋白(GAD67-GFP)基因敲入小鼠制备精神分裂症模型后学习与记忆功能的改变及海马齿状回颗粒细胞层GABA能神经元的表达。方法:利用聚合酶链式反应(PCR)鉴定GAD67-GFP基因敲入小鼠,MK-801连续腹腔注射2周制备精神分裂症动物模型,通过悬尾实验、Morris水迷宫实验、免疫荧光标记技术等,观察GAD67-GFP基因敲入小鼠的学习与记忆功能的改变及GABA能神经元在海马齿状回颗粒细胞层的表达。结果:停药后实验组与对照组比较:(1)实验组体重增加明显低于对照组(P<0.05);(2)行为学改变:1悬尾实验:实验组不动时间明显小于对照组(P<0.05);2Morris水迷宫实验:定位航行实验中实验组逃避潜伏期,游泳总路程明显长于对照组(P<0.05),而其平均游泳速度与对照组没有明显差异(P>0.05);空间探查实验中实验组经过平台所在点的次数和在平台所在象限的时间明显小于对照组(P<0.05);(3)在海马齿状回颗粒细胞层中实验组的GFP阳性细胞明显多于对照组(P<0.05)。结论:通过对GAD67-GFP基因敲入小鼠进行腹腔注射MK-801制备精神分裂症模型后,其学习与记忆功能显著下降,且海马齿状回颗粒细胞层GABA能神经元明显增加。提示精神分裂症后学习记忆功能减退可能与GABA能神经元的表达有关。

Objective： To explore the change of learning and memory function and the expression of GABAergic neurons in the hippocampal dentate gyrus granule cell layer in glutamic acid decarboxylase 67-green fluorescent protein（ GAD67-GFP） knock-in mouse model of schizophrenia. Methods： Polymerase chain reaction（ PCR） was used to identify the GAD67-GFP knock-in mouse. MK-801 was injected intraperitoneally for two weeks to make animal models of schizophrenia. Tail suspension test,Morris water maze test and immunofluorescence labeling techniques were used to observe learning and memory function of GAD67-GFP knock-in mouse and the expression of GABAergic neurons in the hippocampal dentate gyrus granule cell layer. Results： Weight gain in the experimental group was significantly lower than that of the control group（ P〈0. 05）. The tail suspension test showed that the immobility time of experimental group was significantlyless than that of the control group（ P〈0. 05）. Morris water maze experiment showed that navigation test escape latency and the total swimming distance in the experimental group significantly longer than those of the control group（ P〈0. 05）,whereas no significant differences in swimming speed between the groups.（ P〈0. 05）. The number of times passing though the platform and the stay time in the target quadrant of experimental group was significantly shorter than those of control group in space exploration experiments（ P〈0. 05）. In the hippocampal dentate gyrus granular cell layer of the experimental group,the number of GFP positive cells significantly more than that of control group（ P〈0. 05）. Conclusion： In experimental group,there was a significant reduction in the learning and memory function,and the number of GABAergic neurons increased significantly in the hippocampal dentate gyrus granular cell layer. Learning and memory function may be associated with GABAergic neurons expression in schizophrenia.