电针迷走神经对抑郁模型幼鼠海马自噬的影响

Effect of electroacupuncture stimulation of vagus nerve on autophagy of hippocampus in juvenile rats with depression

目的研究电针迷走神经(VNS)对抑郁幼鼠海马细胞自噬的影响。方法利用慢性不可预知性应激(CUS)方法构建幼鼠抑郁模型,随机分为对照组、CUS组、氟西汀组和电针组。使用体质量、摄食量及不动时间评定幼鼠抑郁水平;采用免疫组化检测各组幼鼠海马齿状回区中Beclin1、LC3Ⅰ和mToR表达。结果造模后刺激前,CUS组、氟西汀组和电针组的体质量、摄食量均低于对照组,不动时间长于对照组(P<0.01);刺激后,CUS组体质量、摄食量仍低于对照组,不动时间长于对照组(P<0.01);氟西汀组、电针组体质量、摄食量高于CUS组,不动时间短于CUS组(P<0.01)。CUS组平均光密度高于对照组(P<0.01),但mToR染色强度小于对照组(P<0.01)。氟西汀组、电针组的幼鼠海马齿状回中Beclin1和LC3Ⅰ表达水平低于CUS组,mToR表达水平高于CUS组(P<0.01)。结论电针迷走神经改善CUS诱导抑郁幼鼠模型抑郁症状,可能与抑制海马齿状回区Beclin1、LC3Ⅰ表达,升高mToR表达,从而改善自噬有关。

Objective To explore the effect of electroacupuncture stimulation of vagus nerve on autophagy in hippocampus of juvenile rats with depression.Methods Chronic Unpredictable Stress(CUS)was used to build depression model in juvenile rats,and the rats were randomly divided into control group,CUS group,fluoxetine group and electroacupuncture group.Weight,appetite and immobility time were used to assess the depression level of rats.The expression of Beclin1、LC3Ⅰ、mToR in hippocampus dentate gyrus were measured with immunohistochemistry.Results After modeling,the body weight and appetite of CUS group,fluoxetine group and electroacupuncture group were all significantly lower than those of control group,but the immobility time was longer than that of control group(P<0.01).After treatment,the body weight and appetite of CUS group were all significantly lower than those of control group,and the immobility time was longer than that of control group(P<0.01);the body weight and appetite of fluoxetine group and electroacupuncture group were siginificantly higher than those of CUS group,and the immobility time was significantly shorter than that of CUS group(P<0.01).In CUS group,the average optical density was higher than that in control group(P<0.01),and the staining intensity of mTOR was lower than that in control group(P<0.01).The expression levels of beclin1 and LC3Ⅰin fluoxetine group and electroacupuncture group were significantly lower than those in CUS group,and the levels of mTOR were higher than that in CUS group(P<0.01).Conclusion Vagus nerve stimulation using electroacupuncture could improve the depressive symptoms of juvenile rats with depression,which may be related to that the inhibition of hippocampal dentate gyrus Beclin1,LC3Ⅰexpressions,and higher mToR expression may improve autophagy.