电针对Aβ_(25-35)诱导的阿尔茨海默病大鼠模型海马长时程增强的影响

Effect of Electroacupuncture on Hippocampal LTP in Alzheimer's Disease Rats Induced by Aβ_(25-35)

目的:探讨针刺改善阿尔茨海默病(AD)学习记忆能力衰退的机制。方法:将30只SD大鼠随机分为假手术组、模型组及电针组,每组10只。将10μg Aβ25-35注射于模型组与电针组大鼠的双侧海马齿状回背侧制备AD模型。电针治疗取"大椎""百会""肾俞""涌泉"穴,每次30 min,每日1次,治疗7 d。应用跳台实验和电生理学方法观察电针治疗后AD模型大鼠学习记忆能力和海马突触传递长时程增强(LTP)的变化。结果:与假手术组相比,模型组大鼠跳台错误次数和累计错误时间显著增加(P<0.05,P<0.01);而电针干预治疗可显著改善AD大鼠跳台实验的错误次数和累计错误时间(P<0.05,P<0.01)。模型组大鼠的LTP显著衰退(P<0.01);电针治疗可显著促进AD大鼠LTP恢复(P<0.01)。结论:电针具有改善AD大鼠学习记忆能力的作用,其机制可能与电针恢复海马突触传递LTP有关。

Objective To observe the effect of electroacupuncture（EA） on the learning-memory ability in Alzheimer＇s disease（AD） rats. Methods Thirty SD rats were equally randomized into control, model and EA groups. AD model was estab- lished by injecting β-amyloid （Aβ25-35, 10 μg） into the bilateral dentate gyri of the hippocampal CA 1 area （AP -3.5 mm, ML ±2.0 mm, DV 2.7 mm）. EA （4 Hz, 1 - 2 mA） was applied to ＂Baihui＂ （GV 20）, ＂Dazhui＂ （GV 14）, bilateral ＂Shenshu＂ （BL 23） and bilateral ＂Yongquan＂ （KI 1） for 30 min, once daily for 7 days. The learning-memory ability was detected by using step-down test. Long term potentiation （LTP） of hippocampal CA 1 area was recorded by using tungsten microelectrodes after high frequency stimulation （HFS） conditioning of the cortical anterior perforated substance. Results In AD rats, the error number and total error time of step-down test were increased significantly （P〈0.05, P〈0.01 ） ,and the slope of the excitatory pestsynaptic potential （EPSP）, and the amplitude and area of population spikes （PS） at 30 min, 60 min, 90 min and 120 min after high-frequency stimulation of the cortical anterior perforated substance lowered markedly in comparison with sham operation （control） group （P〈0.05, P〈0.01 ）. After EA treatment, the error number and total error time decreased significantly, the slope of EPSP, and the amplitude and area of PS from 30 min to 120 min after high-frequency stimulation increased considerably in compa- rison with model group（ P〈0.05, P〈0.01 ）, suggesting an improvement of the synaptic transmission after EA. Conclusion EA can improve AD rats＇ learning-memory ability and raise the slope of EPSP and the amplitude of PS, which may contribute to its effect in relieve symptoms of AD in clinic.