针刺对糖尿病合并脑缺血大鼠海马脑片CA1区诱发长时程增强的影响

目的:探讨针刺对糖尿病合并脑缺血大鼠海马脑片诱发长时程增强(LTP)效应的影响。方法:Wistar大鼠54只,随机分为正常对照组(Con)、糖尿病+假手术组(DM+Sham-CI)、脑缺血组(CI)、糖尿病+脑缺血组(DM+CI)、糖尿病+脑缺血+针刺组(DM+CI+Acup)。腹腔注射链脲佐菌素建立糖尿病模型,3d后双侧颈总动脉结扎再灌注2次造成脑缺血模型。针刺治疗从术后1周开始,针刺穴位为"百会"、双侧"三阴交"脾俞"或"百会"、双侧"肾俞"足三里",两组穴位交替进行,留针30min,隔日1次,共治疗15次。术后40d,采用细胞外微电极记录技术,记录大鼠海马脑片CA1区诱发群峰电位(PS),然后施以100Hz、100串的高频刺激诱发LTP。结果:糖尿病合并脑缺血大鼠海马脑片PS的形状、波幅与正常动物没有明显差异,提示其并不影响海马的基础突触传递。给予高频刺激后,Con组可见PS波幅增加、斜率增大,表现为突触传递强度和效率的增强;而DM+CI组脑片在受到高频刺激后,在所观察的60min内,9个时间点PS波幅和斜率基本表现为下降趋势,与同一时间点Con组相比差异有统计学意义(P<0.05,P<0.01);DM+CI+Acup组在给予高频率刺激后,PS波幅和斜率基本表现为上升趋势,与DM+CI组同一时间点相比差异均有统计学意义(P<0.05,P<0.01)。说明糖尿病合并脑缺血大鼠的LTP效应明显降低,而针刺可以改善这种LTP效应的下降。结论:针刺对糖尿病合并脑缺血导致的学习记忆障碍的改善作用可能是通过改善LTP效应,增强突触的可塑性来实现的。

Effect of Acupuncture on Long-term Potentiation of Hippocampal CA1 Area in Diabetic Rats with Concurrent Cerebral Ischemia

Objective To investigate the effect of manual acupuncture on long-term potentiation(LTP)in CA1 area in hippocampal slices from rats suffered from diabetes mellitus(DM)and cerebral ischemia(CI).Methods A total of 54 female Wistar rats were randomly divided into 5 groups:normal control(Con),CI,DM Sham-CI,DM CI and DM CI acupuncture(Acup).DM model was established by i.p.of streptozotocin(60 mg/kg),and CI model duplicated by bilateral common carotid arteries occlusion and reperfusion."Baihui"(GV 20),bilateral "Sanyinjiao"(SP 6)and "Pishu"(BL 20)or "Baihui"(GV 20),bilateral "Shenshu"(BL 23)and "Zusanli"(ST 36)were punctured alternatively and stimulated manually,once every other day for 15 times.Hippocampal slices were taken 40 days after modeling.LTP in hippocampal CA1 induced by high frequency stimulation(100 Hz,100 pulses)of Schaffer collaterals and population spikes(PS)were recorded by using glass micropipettes.Results No significant differences were found between DM CI and normal control groups in the shape and amplitude of PS(P>0.05).After stimulation of Schaffer collaterals,the amplitude and slope rate of PS in hippocampal CA1 of DM CI rats were decreased significantly in comparison with normal control group(P<0.05,P<0.01).While compared with DM CI group,both the amplitude and slope rate of PSin DM CI Acup groupincreased significantly(P<0.05,P<0.01),suggesting basic restoration of LTP after acupuncture.Conclusion Acupuncture can promotethe recovery of DM CI induced decline of the amplitude and slope rate of PS,which may contributetoits effect ini mproving memory abilityin DM CI rats through regulating hippocampal neuronal synaptic plasticity.