不同电针刺激对慢性应激抑郁模型大鼠行为学及海马谷氨酸转运体的影响

目的:观察音乐电针和脉冲电针对慢性应激抑郁模型大鼠行为学和海马神经元及谷氨酸转运体的影响,探讨电针抗抑郁作用的生物学机制,并比较两种电针的疗效差异。方法:SD大鼠随机分为空白组、模型组、氟西汀组、脉冲电针组、音乐电针组,每组12只。采用慢性应激刺激结合孤养的方式建立慢性应激抑郁模型。氟西汀组将盐酸氟西汀按照2mg/kg剂量灌胃给药,电针组给予电针"百会""印堂"穴20min,以上治疗均为每天1次,连续21d。通过旷场实验观察大鼠的行为学变化;用尼氏染色法观察各组大鼠海马神经元数量及形态;用实时荧光定量PCR法检测各组大鼠海马内兴奋性氨基酸转运体(EAATs)EAAT 1、EAAT 2mRNA表达量。结果:与空白组比较,模型组大鼠旷场实验水平运动得分和垂直运动得分明显降低(P<0.01);氟西汀组、脉冲电针组、音乐电针组与模型组比较,大鼠活动度均显著提高(P<0.01)。模型组大鼠海马神经元细胞排列松散、缺失,氟西汀、脉冲电针和音乐电针均可改善此病理变化。模型组大鼠海马内EAAT 1、EAAT 2mRNA表达与空白组比较明显降低(P<0.01);与模型组比较,脉冲电针和音乐电针均可显著提高大鼠海马内EAAT 1、EAAT 2mRNA表达量(P<0.01)。结论:氟西汀、脉冲电针和音乐电针均可改善慢性抑郁大鼠行为学及海马内神经元的形态及数量;脉冲电针、音乐电针在上调大鼠海马内EAAT 1、EAAT 2mRNA表达方面明显优于氟西汀;脉冲电针和音乐电针可通过增加海马EAAT 1、EAAT 2mRNA表达,改善谷氨酸再循环,发挥抗抑郁作用。

Effect of Electroacupuncture Intervention on Behavioral Changes and Hippocampal Excitatory Amino Acid Transporter mRNA Expression in Depression Rats

Objective To observe the influence of music-electroacupuncture(EA) and pulse EA on locomotor activity and hippocampal neuron numbers and excitatory amino acid transporters(EAATs) mRNA expression in depression rats,so as to explore their mechanisms underlying improvement of depression in acupuncture clinic.Method Sixty SD rats were randomly divided into blank control,depression model,medication,pulse EA and music-EA groups,with 12 rats in each group.Depression model was established by using chronic unpredictable mild stress protocols combined with solitary feeding.Rats of the medication group were treated by oral administration of fluoxetine(a standard antidepressant,2 mg/kg).EA was applied to "Baihui"(GV 20) and "Yintang"(EX-HN 3) for 20 min,once a day for 21 days.The animals' ethological changes were detected by using field tests for recording the number of crossing squares and the number of rearing.The number of hippocampal neurons were calculated under microscope after Nissl's staining of the hippocampal tissue section.Hippocampal EAAT 1 and EAAT 2 mRNA expression levels were assayed by fluorescent quantitative real-time PCR.Results In comparison with the blank control group,the numbers of crossing and rearing movements,as well as the expression levels of hippocampal EAAT 1 and EAAT 2 mRNA were significantly lower in the model group(P<0.01),while compared with the model group,the numbers of both crossing and rearing movements of the medication,pulse EA and music-EA groups were obviously increased(P<0.01).Correspondingly,the expression levels of hippocampal EAAT 1 and EAAT 2 mRNA were considerably upregulated in the pulse EA and music-EA groups in comparison with the model group(P<0.01).No significant differences were found among the medication,pulse EA and music-EA groups(P>0.05).Results of Nissl's staining displayed that in the model group,the hippocampal neurons were loose in arrangement and some of them were absent,but in the medication,pulse EA and music-EA groups,the neurons were clear in shape and lined in order.Conclusion Both pulse EA and music-EA can effectively improve the locomotor activity and hippocampal neuronal structure in depression rats which may be closely associated with their effects in upregulating hippocampal EAAT 1 and EAAT 2 mRNA expression.