电针对血管性痴呆大鼠海马NMDAR-2 B mRNA表达及学习记忆能力的影响

目的:探讨电针改善血管性痴呆(VD)大鼠学习记忆能力的作用机制。方法:将成年雄性SD大鼠采用永久性结扎双侧颈总动脉法建立VD模型,设立空白组、假手术组、模型组、电针非穴位组和电针穴位组,每组各10只。电针穴位组选取"百会"大椎"和双侧"肾俞"穴,电针非穴位组选取第1腰椎和第2腰椎两侧胸腹交界处的非穴位点,每天1次,每次20 min,连续30 d。Morris水迷宫检测大鼠学习记忆能力,用原位杂交技术测定大鼠海马CA1区和齿状回N-甲基-D-天冬氨酸受体(NMDAR)-2 B mRNA的表达。结果:与空白组比较,模型组平均逃避潜伏期延长,平台所在象限停留时间缩短,海马结构NMDAR-2 B mR-NA表达减少(P<0.05)。与模型组相比,电针穴位组的平均逃避潜伏期缩短,平台所在象限停留时间延长,海马结构NMDAR-2 B mRNA表达增高(P<0.05);电针非穴位组与模型组比较,各项指标无明显变化。结论:电针穴位可以提高VD大鼠海马CA1区及齿状回NMDAR-2 B mRNA的表达,增强学习记忆能力。

Effect of Electroacupuncture on NMDAR-2BmRNA Expression in Hippocampal Tissue in Vascular Dementia Rats

Objective To study the underlying mechanism of electroacupuncture(EA) in improving learning-memory ability in vascular dementia(VD) rats.Methods SD rats were randomized into control,sham operation(sham),VD model,non-acupoint and acupoint groups,with 10 cases in each.VD model was established by occlusion of the bilateral common carotid arteries.Morris water maze test was performed to detect the rats' learning-memory ability.The expression of N-methyl-D-aspartate receptor(NMDAR)-2 B mRNA in hippocampal CA 1 region and dentate gyrus was measured by hybridization in situ.EA(2 Hz,1-2 mA)was applied to "Baihui"(GV 20),"Dazhui"(GV 14) and bilateral "Shenshu"(BL 23) and non-acupoint(the chest-abdominal juncture between the first and the second lumbar vertebrae) for 20 min,once daily for 30 days.Results Self-comparison showed that 6 weeks after modeling,the escape latencies of control and sham groups,and the lingering duration in the 3rd quadrant of water pool of model,non-acupoint and acupoint groups decreased significantly(P<0.05),while the escape latencies of model,non-acupoint and acupoint groups,and the lingering duration of control and sham groups increased considerably(P<0.05).No significant differences were found between control and sham groups,and among model,non-acupoint and acupoint groups in the escape latency and the lingering duration in the 3rd quadrant(P>0.05).On the 11th week after modeling,compared to their individual escape latencies and lingering duration on the 6th week,the escape latencies of control,sham and acupoint groups shortened obviously(P<0.05),while the lingering duration in the 3rd quadrant of the same 3 groups postponed significantly(P<0.05).Compared with model group,the escape latency of acupoint group shortened obviously and the lingering duration increased significantly(P<0.05).No significant differences were found between control and sham groups,and between modeland non-acupoint groups in these two indexes(P>0.05).Compared to control/sham group,the grey values of NMDAR-2 B mRNA expression in hippocampal CA 1 region and dentate gyrus in model and non-acupoint groups decreased significantly(P<0.05).Compared to model group,the grey values of NMDAR-2 B mRNA expression in these two brain regions increased markedly(P<0.05).No significant difference was found between control and sham groups,and between model and non-acupoint groups(P>0.05).Conclusion Acupoint-EA is able to improve VD rats' learning-memory ability which may be related to its effect in upregulating the expression of NMDAR-2 B mRNA in hippocampal and dentate gyrus.