电针对慢性应激抑郁大鼠学习记忆与海马神经元损伤的影响

目的:观察电针对慢性应激抑郁大鼠海马神经元的保护作用。方法:将SD大鼠随机分为正常组、模型组、电针组和氟西汀组,每组12只。采用慢性不可预知的温和应激方法建立抑郁症大鼠模型。电针组给予电针"百会""印堂"穴,每次20min,每日1次,共治疗21d;氟西汀组给予氟西汀3.3mg/kg灌胃治疗,每日1次,共21d。实验第1、7、14、21天检测大鼠体质量,Morris水迷宫实验观察动物行为学,HE染色检测海马的组织结构,透射电镜观察海马超微结构。结果:与正常组比较,模型组大鼠体质量显著下降(P0.01),水迷宫实验的潜伏期和游泳总路程显著延长(P0.01),海马神经元严重损伤,结构发生明显改变。电针治疗可以显著增加大鼠体质量(P0.05),缩短潜伏期和游泳总路程(P0.01),减轻海马神经元损伤。结论:电针可以改善慢性应激引起的大鼠海马神经元损伤,这可能是针刺缓解学习记忆能力的下降,治疗抑郁症的作用机制之一。

Effect of Electroacupuncture Intervention on Learning-memory Ability and Injured Hippocampal Neurons in Depression Rats

Objective To observe the effect of electroacupuncture(EA)stimulation of"Baihui"(GV 20)-"Yintang"(EX-HN 3)on changes of learning-memory ability and hippocampal neuron structure in chronic stress-stimulation induced depression rats.Methods Forty-eight SD rats were randomly divided into normal,model,EA and medication(Fluoxetine)groups, with 12rats in each group.The depression model was established by chronic unpredictable mild stress stimulation(swimming in 4℃ water,fasting,water deprivation,reversed day and night,etc).Treatment was applied to"Baihui"(GV 20)and"Yintang"(EX-HN 3)for 20min,once every day for 21days.For rats of the medication group,Fluoxetine(3.3mg/kg)was given by gavage(p.o.),once daily for 21days.The learning-memory ability was detected by Morris water maze tests.The pathological and ultrastructural changes of the hippocampal tissue and neurons were assessed by H.E.staining,light microscope and transmission electron microscopy,respectively.Results Compared to the normal group,the rats' body weight on day 14and day 21after modeling was significantly decreased in the model group(P<0.01),the escape latency and total swimming distance in the 4 quadrants on day 10and 21were significantly increased in the model group(P<0.01).In comparison with the model group,the body weight on day 14and 21were significantly increased(P<0.05),and the escape latency and total swimming distance levels were significantly decreased in the EA group(P<0.01),suggesting an improvement of learning-memory ability.Observations of light microscope and transmission electron microscope showed that modeling induced pathological changes such as reduction in hippocampal cell layers,vague and broken cellular membrane,and ultrastructural changes of hippocampal neurons including swelling and reduction of mitochondria and mitochondrial crests were relived after EA and Fluoxetine treatment.Conclusion EA intervention can improve the learning-memory ability and relieving impairment of hippocampal neurons in depression rats,which may be one of its mechanisms underlying bettering depression.