重复经颅磁刺激对抑郁模型大鼠行为学及海马区糖皮质激素受体表达的影响

目的观察重复经颅磁刺激(repetitive transcranial magnetic stimulation,r TMS)对慢性应激抑郁模型大鼠的抗抑郁作用及对海马区糖皮质激素受体(glucocorticoid receptor,GR)表达的影响,探讨r TMS抗抑郁作用的可能机制。方法 75只健康成年雄性大鼠随机分为造模组(60只)和空白对照组(15只),造模组采用孤养联合慢性温和不可预见应激(chronic unpredictability stimulus,CUMS)方法制备抑郁大鼠模型,为期3周,筛选造模成功的大鼠45只随机分为r TMS组、伪r TMS组和抑郁对照组,每组15只,r TMS组和伪r TMS组分别接受10 Hz的r TMS刺激和伪刺激干预3周,抑郁对照组和空白对照组不给予干预。分别于造模前、造模后、r TMS干预后进行体重测量、蔗糖水消耗实验和强迫游泳实验评估,r TMS干预后检测大鼠海马区GR蛋白和海马GR m RNA表达水平。结果造模后,r TMS组、伪r TMS组和抑郁对照组大鼠蔗糖水消耗量较空白对照组下降,强迫游泳不动时间增加(P0.01)。r TMS干预后,r TMS组体重增长率、蔗糖水消耗量与伪r TMS组和抑郁对照组相比均较高(P0.01),强迫游泳不动时间较短(P0.01)。伪r TMS组及抑郁对照组海马区GR蛋白及其m RNA表达水平与r TMS组和空白对照组相比均较低(P0.05)。结论 r TMS能够改善CUMS抑郁模型大鼠的抑郁样行为,可能与上调海马区GR表达有关。     

不同刺激参数rTMS对慢性不可预见应激大鼠行为的作用及大脑BDNF水平的影响

目的 观察不同刺激参数重复经颅磁刺激（rTMS）对慢性不可预见应激（CUS）模型大鼠行为学的作用,并观察其对大鼠脑源性神经营养因子（BDNF）水平的影响.方法 64只SD大鼠随机分为对照组（8只）、模型组（8只）和干预组（共6个亚组,每组8只）.对照组正常饲养21d后连续7d给予rTMS假刺激;模型组在造模后连续7d给予rTMS假刺激;干预组在造模后每天给予不同频率和强度的rTMS刺激,连续7d.实验期间观察大鼠体质量的变化,并采用运动箱和强迫游泳实验评估大鼠抑郁样行为,最后以酶联免疫吸附法测定大脑BDNF的水平.结果 （1）造模结束后,对照组大鼠的体质量、强迫游泳静止时间与其他两组相比均存在显著性差异（P＜0.01,P＜0.05）,而模型组和干预组大鼠比较没有上述差异（P＞ 0.05）.各组大鼠水平运动距离没有显著性差异（P＞0.05）.（2）rTMS干预后,①模型组大鼠的体质量显著低于对照组及干预组（5 Hz,0.84/1.26 T和10 Hz,0.84/1.26 T） （P ＜0.05）.②各组大鼠水平运动距离之间没有显著性差异;模型组强迫游泳静止时间百分比明显高于对照组及干预组（P＜0.05）.③模型组BDNF的水平低于对照组,而一定刺激条件的rTMS可以改善这一现象.④双因素方差分析显示,刺激频率可能是改善大鼠抑郁行为和调节BDNF的关键因素,而且5 Hz的抗抑郁效应更为显著.结论 不同刺激参数的rTMS对CUS动物抑郁行为的改善作用存在差异,大脑BDNF水平的变化可能参与了这一改善过程.     

重复经颅磁刺激通过调节海马的核因子转录因子抗氧化信号通路改善慢性不可预见应激大鼠的抑郁样行为北大核心CSCD

目的探讨重复经颅磁刺激(rTMS)对慢性不可预见应激(CUS)大鼠抑郁行为及海马区核因子转录因子(Nrf2)抗氧化基因表达的影响。方法将24只SD雄性大鼠按安全随机法分为对照组、CUS组、CUS+rTMS组,每组各8只。适应性饲养7 d后,CUS组、CUS+rTMS组大鼠给予CUS刺激,然后给予CUS+rTMS组大鼠5 Hz的rTMS刺激干预7 d,其他组接受假刺激。最后一次rTMS干预结束24 h后进行糖水偏好、旷场和强迫游泳测试,随后处死动物,通过实时定量PCR(RT-PCR)和蛋白免疫印迹法检测海马的Nrf2、血红素加氧酶1(HO-1)和超氧化物歧化酶1(SOD-1)的表达变化。将另外24只大鼠按安全随机法分为3组:对照病毒+CUS组、对照病毒+CUS+rTMS组、Nrf2下调病毒(shNrf2)+CUS+rTMS组,每组各8只;对照病毒+CUS组、对照病毒+CUS+rTMS组大鼠海马注射对照病毒,shNrf2+CUS+rTMS组大鼠海马注射shNrf2。注射病毒2周后,均接受CUS刺激,然后给予rTMS(5 Hz)或假刺激干预7 d。干预结束24 h后进行行为学及分子生物学检测。结果(1)与对照组相比,CUS组大鼠糖水偏好减少[(39.33±11.85)%比(77.31±4.69)%;F=8.32,P<0.01],旷场中心活动时间减少[(14.70±4.27)s比(52.49±1.07)s;F=3.84,P<0.05)],强迫游泳不动时间增加[(38.70±4.27)s比(24.19±1.07)s;F=10.31,P<0.01)],海马Nrf2、HO-1和SOD-1表达下调(P<0.05);(2)与CUS组相比,CUS+rTMS组大鼠的糖水偏好和旷场中心活动时间增加(均P<0.05),强迫游泳不动时间减少(P<0.05),海马Nrf2、HO-1和SOD-1表达上调(P<0.05)。(3)与对照病毒+CUS+rTMS组相比,shNrf2+CUS+rTMS组大鼠海马Nrf2及下游靶基因HO-1和SOD-1表达下调(P<0.05),大鼠的糖水偏好和旷场中心活动时间减少(均P<0.05),强迫游泳不动时间增加(P<0.05)。结论 rTMS通过调节CUS大鼠海马Nrf2及其下游分子HO-1和SOD-1表达而缓解CUS大鼠的抑郁行为,发挥抗抑郁效果。     

艾司西酞普兰对抑郁模型大鼠行为学及脑脊液、血清脑源性神经营养因子水平的影响

目的:探讨艾司西酞普兰对慢性应激致抑郁模型大鼠行为学及脑脊液、血清脑源性神经营养因子(BDNF)水平的影响。方法:将Sprague Dawley(SD)雄性大鼠随机分为应激组和非应激组,应激组给予慢性不可预知温和应激(CUMS)刺激8周;刺激4周后根据行为学评估[包括强迫游泳实验(FST)、蔗糖水偏爱实验(SPT)、旷场实验(OFT)]及体质量将抑郁行为大鼠随机分为抑郁模型组和抑郁给药组,非应激组随机分为正常对照组和正常给药组,各组6只。第5周起给予两给药组艾司西酞普兰(10 mg/kg·d)腹腔注射4周。刺激及给药结束后对各组大鼠再次行为学评估并检测脑脊液、血清BDNF水平。结果:CUMS 4周后,与非应激组相比,应激组FST中不动时间显著延长,SPT显著降低,OFT中路程及站立次数显著减少,体质量显著降低(P均0.01);药物干预4周后,与抑郁模型组相比,抑郁给药组FST中不动时间显著缩短,SPT及OFT中总路程显著增加(P均0.05);脑脊液、血清BDNF水平抑郁模型组显著低于正常对照组,抑郁给药显著高于抑郁模型组(P0.05或P0.01)。结论:艾司西酞普兰可改善抑郁大鼠的抑郁行为,提高脑脊液及血清BDNF水平。     

重复经颅磁刺激对血管性痴呆大鼠海马CA1区BDNF、NMDAR1、SYN表达及超微结构的影响

目的研究重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)对血管性痴呆大鼠海马CA1区脑源性神经营养因子(brain derived neurotrophic factor,BDNF)、N-甲基-D-天冬氨酸受体亚单位NR1(N-meth-yl-D-aspartate receptor,NMDAR1)和突触素(synaptophysin,SYN)表达及超微结构的影响,进一步探讨rTMS治疗血管性痴呆的分子机制。方法将36只雄性Wistar大鼠随机分为4组:正常对照组10只、痴呆模型组10只、低频刺激组8只和高频刺激组8只。采用两血管阻断法制备血管性痴呆模型。低频刺激组大鼠接受频率0.5Hz重复经颅磁刺激,高频刺激组大鼠接受频率5Hz重复经颅磁刺激。采用Morris水迷宫测试方法测试各组大鼠空间学习记忆力。应用免疫组织化学方法检测海马CA1区BDNF、NMDAR1、SYN蛋白表达情况,应用透射电镜观察海马CA1区超微结构变化。结果 Morris水迷宫测试结果及透射电镜观察均显示磁刺激组大鼠较痴呆模型组大鼠均有好转。痴呆模型组大鼠BDNF、NMDAR1、SYN蛋白表达量比正常对照组大鼠减低(P0.05),低频刺激组和高频刺激组BDNF、NMDAR1、SYN蛋白表达量均比痴呆模型组增高(P0.05),低频刺激组与高频刺激组之间差异无统计学意义(P0.05)。结论重复经颅磁刺激对血管性痴呆有恢复治疗作用,其机理可能与rTMS能增加大鼠海马CA1区BDNF、NMDAR1和SYN的表达。     

雌激素对脑卒中后抑郁大鼠海马和杏仁核脑源性生长因子-磷酸化酪氨酸激酶B表达以及行为学的影响

目的通过观察雌激素对缺血性脑卒中后抑郁大鼠模型海马和杏仁核的脑源性生长因子(BDNF)-磷酸化酪氨酸激酶B(pTrkB)的表达,探讨缺血性脑卒中后内源性抑郁的发病机制。方法将SD雌性大鼠随机分为对照组12只(无任何干预)、模型组16只(MCAO术后2周,皮下注射大豆油,持续2周)和雌激素组16只(MCAO术后2周,皮下注射溶有10μg 17β-雌二醇的0.1 mL大豆油,持续2周)。通过旷场实验和强迫游泳实验观察大鼠行为学变化,应用免疫组化和Western blot方法观察海马和杏仁核中BDNF和pTrkB表达。结果雌激素干预后:①旷场实验和强迫游泳中,大鼠行为学评分均显著提高,雌激素组与模型组比较,差异有统计学意义(P0.01);②免疫组化法观察示雌激素组海马和杏仁核BDNF阳性细胞数与模型组比较明显增多,差异有统计学意义(P0.05);③Western blot法检测示雌激素组BDNF/β-actin和pTrkB/TrkB灰度比值较模型组明显提高(P0.05)。结论雌激素能改善脑卒中后大鼠的抑郁行为,其机制可能是通过BDNF-pTrkB信号通路的变化而改善PSD症状。     

氟西汀对卒中后抑郁大鼠海马脑源性神经营养因子表达的影响

目的 分析卒中后抑郁（post-stroke depression，PSD）模型大鼠海马脑源性神经营养因子（Brainderived neurotrophic factor，BDNF）蛋白及mRNA表达水平，及抗抑郁剂氟西汀干预后BDNF表达水平的变化，初步探讨BDNF在PSD发生中的作用。方法 大脑中动脉阻塞（Middle cerebral artery occlusion，MCAO）法建立局灶脑缺血模型，加用慢性不可预见温和应激（Chronic unpredictable mild stress，CUMS）结合孤养，建立PSD大鼠模型，并予以氟西汀干预。应用蛋白免疫印迹（Western-blot）、Real time-PCR分别检测应激18、28 d时海马BDNF蛋白及mRNA表达水平。结果 与对照组相比，应激14d后PSD组较对照组大鼠体重与糖水消耗比例降低，水平、垂直试验得分下降（P <0.05或P <0.01）。氟西汀干预组糖水消耗比例，水平、垂直试验得分均较PSD组显著增加（P <0.05或P <0.01）。第18、28天，PSD组BDNF蛋白水平较对照组均显著下降（P <0.05或P <0.01）。PSD组BDNF mRNA的表达在应激18d时较正常组有下降趋势，但无统计学意义；至28 d时，表达含量明显下降，差异有统计学意义（P <0.01）。第18、28天，氟西汀干预组BDNF蛋白及mRNA水平均较PSD组显著增加（P <0.01）。结论 应用MCAO模型联合CUMS加孤养模型制备的PSD大鼠模型在神经功能缺损的同时，表现快感缺乏和探索行为减少的抑郁核心症状，并且体重的增长幅度显著减慢。PSD大鼠海马BDNF蛋白及mRNA表达水平显著降低，氟西汀干预后BDNF表达水平上升，初步提示BDNF在卒中后抑郁发生中的作用。     

重复经颅磁刺激对酒依赖患者记忆功能及海马代谢的影响

目的 探讨重复经颅磁刺激(rTMS)对酒依赖患者戒断期记忆功能的影响及与海马代谢物水平变化的关系.方法 将38例男性戒断期酒依赖患者按随机数字表分为rTMS组和伪rTMS组,rTMS组给予1 Hz刺激4周,刺激部位为右侧背外侧前额叶皮质(DLPFC);伪rTMS组给予无效刺激.治疗前后分别评估言语记忆、视觉记忆,并采用氢质子磁共振波谱(1 H-MRS)检测双侧海马部位代谢物N-乙酰基天门冬氨酸(NAA)、胆碱化合物(Cho)和肌酸复合物(Cr).结果 (1)rTMS组治疗后言语记忆和视觉记忆评分较治疗前提高(P<0.05),而伪rTMS组治疗后记忆评分较治疗前差异无统计学意义(P>0.05).治疗后,rTMS组仅视觉记忆评分优于伪rTMS组,差异有统计学意义(P<0.01),而言语记忆未见明显改善(P>0.05).(2)rTMS组治疗后双侧海马NAA/Cr、Cho/Cr较治疗前升高(P<0.01),而伪rTMS组治疗前后双侧海马NAA/Cr、Cho/Cr的差异无统计学意义(P>0.05).治疗后,rTMS组双侧海马NAA/Cr、Cho/Cr高于伪rTMS组,差异有统计学意义(P<0.01).(3)左侧海马NAA/Cr、右侧海马Cho/Cr治疗后与治疗前的差值分别与言语记忆、视觉记忆评分呈正相关(P<0.01).结论 rTMS可以改善戒断期酒依赖患者的记忆功能,其可能机制与升高海马NAA/Cr和Cho/Cr有关.     

低频重复经颅磁刺激对颞叶癫痫大鼠海马NF-κB及COX-2表达的影响

目的 研究低频重复经颅磁刺激(rTMS)对颞叶癫痫模型大鼠海马核转录因子κB(NF-κB)和环争化酶2(COX-2)表达的影响,进而从炎症反应角度探讨rTMS治疗癫痫的可能机制.方法 30只雄性SD大鼠随机分为颞叶癫痫刺激组(TIE+rTMS)、颢叶癫痫假刺激组(TLE+s-rTMS)和生理盐水对照组(NS),每组10只.利用立体定位仪向大鼠海马CA,区微量注射海人酸(KA)制备颞叶癫痫模型,对照组于同部位注射等量生理盐水.刺激组连续接受rTMS治疗10d.采用免疫组织化学染色、蛋白质印迹法(western blotting)研究大鼠海马NF-κBp65和COX-2表达情况.结果 与生理盐水对照组大鼠比较,造模后大鼠海马组织中NF-κBp65和COX-2表达明显增强NF-κBp65核移位增多,差异均有统计学意义(P＜0.05),TLE+rTMS组大鼠海马组织中NF-κBp65和COX-2表达较TLE+s-rTMS组明显降低,NF-κBp65核移位减少,差异均有统计学意义(P＜0.05).结论 rTMS可能通过降低癫痫大鼠海马NF-κB和COX-2的表达,阻止NF-κB核移位,从而抑制炎症反应发挥抗癫痫作用.     

抑郁状态下大鼠海马Notch1信号系统的改变

目的 了解大鼠抑郁模型中海马神经重塑障碍与Notch1信号系统功能改变的关系.方法 54只大鼠随机分为CUMS 14 d组、CUMS 28 d组和对照组,前两组接受慢性不可预知温和应激和孤养(chronic unpredictable mild stress,CUMS)14 d和28 d建立抑郁模型.采用免疫组化、免疫荧光、RT-PCR和Western blot 法.测定大鼠海马神经干细胞的增殖、存活和分化以及Notch1信号通路各个因子的基因及蛋白表达水平的改变.结果 与对照组比较,CUMS 14 d组和CUMS 28 d组大鼠海马神经干细胞增殖与存活明显减少(P<0.001).CUMS 28 d组大鼠海马神经干细胞分化NeuN/BrdU、GFAP/BrdU比例无明显差异(P>0.05).与对照组比较.CUMS 14 d组和CUMS 28 d组Notch1信号通路各因子(NICD、Hes1、Hes5和Jag1)基因表达和蛋白水平明显降低(P<0.01).结论 抑郁大鼠海马齿状回神经干细胞增殖和存活受到抑制,但分化无改变;同时,大鼠海马Notch1功能下调.提示Notch1信号系统可能与抑郁症海马神经再生障碍有关.     

Role of brain-derived neurotrophic factor and neuronal nitric oxide synthase in stress-induced depression*★

BACKGROUND： Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor （BDNF） participates in hippocampal dendrite growth. OBJECTIVE： To discuss the role of BDNF and neuronal nitric oxide synthase （nNOS） in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS： Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine （Xi＇an, China）. BDNF antibody and nNOS antibody were provided by Santa Cruz （USA）. K252a （BDNF inhibitor） and 7-NI （nNOS inhibitor） were provided by Sigma （USA）. METHODS： Animals were randomly divided into five groups： Control group, chronic unpredicted mild stress （CUMS） group, K252a group, K252a＋7-NI group and 7-NI＋CUMS group. While the Control, K252a and K252a＋7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a＋7-NI group, and 1 μL of 7-NI in the 7-NI＋CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES： ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS： Compared with the Control     

Long-lasting effects of chronic rTMS to treat chronic rodent model of depression

Repetitive transcranial magnetic stimulation (rTMS) has been demonstrated in the pre-clinical and clinical settings to have an antidepressant effect. However, studies on the long-lasting effect of rTMS, especially when the effect is measured after treatment has ceased for a few weeks is lacking. We examined this question in a chronic unpredicted mild stress (CUMS) rat model of depression. We gave 3 weeks of high frequency (15 Hz) rTMS, venlafaxine, or these two treatments combined to a modified CUMS paradigm, and then investigated the prolonged effect of treatments. Behavioral testing (sucrose preference test, open field test, forced swimming test, novelty suppressed feeding test), plasma hormone level, hippocampal BrdU labeling, and amount of related neurotropic factors were used to assess the effects of stress and treatments. Long-term chronic rTMS significantly reversed andehonic-like behavior, increased hippocampus cell proliferation, BDNF protein level, phosphorylation of ERK1/2 compared with CUMS rats two weeks after the cessation of rTMS treatment. However, the changes in plasma hormone level were not sustained for that amount of time. Venlafaxine had no interaction with the physical stimulation. Our results suggest that high frequency rTMS has long-lasting effects, which may have some relationship with neuroplasticity.     

Effects of ginsenoside on brain-derived neurotrophic factor and tyrosine kinase B mRNA expression in the hippocampal formation of aged rats

BACKGROUND:There are a limited number of studies involving the effects of ginsenosides,the active component of ginseng,on expression of hippocampal TrkB mRNA in aged rats.OBJECTIVE:To observe expression of brain-derived neurotrophic factor(BDNF) and tyrosine kinase B (TrkB)mRNA in the hippocampal formation of aged rats,as well as changes after ginsenoside administrated.DESIGN,TIME AND SETTING:A randomized,controlled experiment was performed at the Department of Anatomy,College of Basic Medical Sciences,China Medical University in March 2005.MATERIALS:A total of 39 female,Wistar rats were randomly divided into 3 groups (n=13 each):young (3-5 months old),aged(27 months old),and ginsenoside group(received 25mg/kg/d ginsenoside in the drinking water between 17 and 27 months of age).METHODS:Following anesthesia,the rats were exsanguinated and perfused transcardially with chilled,heparinized,0.9% saline.The brains were removed and post-fixed in 40 g/L paraformaldehyde/phosphate buffer for 20 minutes,and further incubated in 30% sucrose/phosphate buffer overnight.MAIN OUTCOME MEASURES:In situ hybridization,immunohistochemistry,and image analysis were used to investigate expression of BDNF and Trk(B mRNA in the hippocampal formation.RESULTS:The expression levels of BDNF in the hippocampal CA3 and CA1 of aged rats was significantly less than the young group(t=2.879,1.814,1.984,P<0.05).BDNF expression was significantly greater in the dentate gyrus of the ginsenoside group,compared with the aging group(t=1.943,P<0.01).The expression of TrkB mRNA in the hippocampal CA3,CA1,and dentate gyrus of aged rats was less than the young group(t=3.540,3.629,17.905,P<0.01).TrkB mRNA expression in the CA3 region and dentate gyrus of the ginsenoside group was significantly greater compared with the aging group(t=1.293,3.386,P<0.05.0.01).CONCLUSION:BDNF and TrkB mRNA expression in the hippocampal formation were reduced in the aged group.However,ginsenosides can increase BDNF and TrkB mRNA expression in the hippocampal formation.     

艾司西酞普兰对抑郁大鼠海马BDNF表达及细胞凋亡的影响

目的观察艾司西酞普兰对抑郁大鼠海马BDNF表达及细胞凋亡的影响,探讨其作用机制。方法40只雄性SD大鼠随机分为对照（A）、对照＋药（B）、抑郁模型（C）和抑郁模型＋药（D）组共4组,采用慢性不可预见性的温和刺激结合孤养法建立抑郁大鼠模型,TUNEL法检测海马细胞凋亡情况,实时荧光定量PCR方法检测海马BDNF、Bax、Bcl2、Caspase3mRNA的表达。结果（1）C组海马细胞凋亡数显著增加,与A组比较差异有统计学意义（P〈0．01）,而B组细胞凋亡数与A组差异无统计学意义（P〉0．05）;D组细胞凋亡数明显减少,与c组比较差异有统计学意义（P〈0．01）。（2）C组海马BDNF、Bel—2mRNA表达降低,Bax、Caspase3mRNA表达升高,与A组比较差异均有统计学意义（P〈0．01）;D组BDNF、Bcl2mRNA表达增加,Bax、Caspase3mRNA表达降低,与C组比较差异均有统计学意义（P〈0．01）。结论艾司西酞普兰可改善抑郁大鼠的抑郁行为及海马细胞凋亡,其机制可能是通过增加海马BDNFmRNA的表达,上调Bcl一2及下调Bax、Caspase3mRNA的表达,从而预防海马细胞凋亡而发挥脑保护的作用。     

Overexpression of brain-derived neurotrophic factor in the hippocampus protects against post-stroke depression

Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor(BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippocampus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.     

The Restoration After Repetitive Transcranial Magnetic Stimulation Treatment on Cognitive Ability of Vascular Dementia Rats and Its Impacts on Synaptic Plasticity in Hippocampal CA1 Area

The purposes of this research were to study the restoration on the cognitive ability of rat models with vascular dementia (VaD) by repetitive transcranial magnetic stimulation (rTMS) treatment and its impacts on synaptic plasticity in hippocampal CA1 area and to further explore the molecular mechanisms of the rTMS treatment on vascular dementia. Thirty-six male Wistar rats were randomly divided into four groups: the normal control group, the vascular dementia model group, the low-frequency rTMS group, and the high-frequency rTMS group. Two-vessel occlusion was employed to make VaD models. Low-frequency rTMS group rats were treated with 0.5 Hz rTMS for 6 weeks. High-frequency rTMS group rats underwent 5 Hz rTMS for 6 weeks. Morris water maze was carried out to detect the ability of spatial learning and memory of rats. The ultra-structural changes of synapses in four groups were observed by transmission electron microscope. Then the expressions of brain-derived neurotrophic factor (BDNF), NMDAR1, and Synaptophysin (SYN) mRNA and proteins in hippocampal CA1 area were determined by real-time PCR, western blot, and immunohistochemistry assay. After rTMS treatment, the learning and memory abilities of VaD rats improved significantly. The ultra-structures of synapses in hippocampal CA1 area in rTMS groups were reformed. The mRNA and protein expressions of BDNF, NMDAR1, and SYN in the low-frequency rTMS group and in the high-frequency rTMS group were higher than that in VaD model group (P < 0.05). rTMS plays an important and beneficial role in the restoration treatment of vascular dementia, which may be related to the mechanism that rTMS can increase the mRNA and protein expressions of BDNF, NMDAR1, and SYN and affect the synaptic plasticity in hippocampal CA1 area.     

Notch1信号系统与抑郁模型大鼠海马神经重塑障碍

目的 探讨Notch1信号系统在抑郁海马神经再生障碍中的作用.方法 选择行为学评分相近的68只Sprague-Dawley大鼠,分为对照组、对照+氟西汀组、慢性不可预知温和应激(CUMS)组,CUMS+氟西汀组,每组17只.应用CUMS建立抑郁模型后进行行为学评估;采用免疫组织化学方法检测大鼠海马神经干细胞的增殖和存活;采用实时定量聚合酶链反应和蛋白免疫印迹方法测定Notchl信号通路各个因子(NICD、Hes1、Hes5、Jag1)的基因及蛋白表达水平的改变.结果 (1)干预前,各组体质量、糖水偏好、旷场试验、强迫游泳评分的差异均无统计学意义(P>0.05);干预后,与对照组比较,CUMS组糖水偏好、水平得分和垂直得分降低,漂浮不动时间增加,差异均有统计学意义(P<0.001);与CUMS组比较,CUMS+氟西汀组糖水偏好、水平得分和垂直得分增加,漂浮不动时间降低,差异均有统计学意义(P<0.01);(2)神经干细胞的增殖和存活:与CUMS组(1900.33±104.10)比较,CUMS+氟西汀组(3047.61±158.29)神经干细胞的增殖数显著上升,差异有统计学意义(P<0.01);与CUMS组(1845.33±126.88)比较,CUMS+氟西汀组(2704.21±154.31)神经干细胞的存活数显著上升,差异有统计学意义(P<0.01);(3)海马Notch1信号通路基因和蛋白的表达:CUMS+氟西汀组小鼠抗大鼠Notch1(NICD)mRNA、Hes1 mRNA、Hes5 mRNA、Jag1 mRNA基因表达与CUMS组比较显著上升,差异均有统计学意义(P<0.01);CUMS+氟西汀组NICD、Hes5、Jag1蛋白水平与CUMS组比较显著上升,差异均有统计学意义(P<0.01).结论 Notch1信号系统可能参与慢性应激模型大鼠海马神经再生障碍;氟西汀可能通过上调Notch1信号系统改善海马神经再生,从而缓解大鼠抑郁症状.

Abstract：

Objective To investigate whether the effect of fluoxetine on hippocampal neurogenesis involves Notch1 signaling after chronic stress. Methods Sixty-eight male Sprague-Dawley rats were divided into control group, control + fluoxetine group, depression model group and depression model + fluoxetine group. Chronic unpredictable mild stress (CUMS) was used to make up depression animal model. The function of Notch1 signaling was measured by real-time PCR and western blotting. Simultaneously,hippocampal neurogenesis was monitored by assessing cell proliferation and survival. Results (1) Before starting CUMS protocol, the animals exhibited equivalent weight, sucrose preference, number of squares crossed, number of rearing, and immobility time in behavioral test. Twenty-eight days after CUMS protocol,these parameters were significantly difference in rats exposed to CUMS compared with the controls (sucrose preference, number of squares crossed, number of grooming and rearing, and immobility time, P<0. 01).Administration of fluoxetine was shown to dramatically improve the depression behavior (P<0. 01) .(2) The cell proliferation [(3047. 61 ± 158. 29) vs. (1900. 33 ± 104. 10)] and survive [(2704. 21 ±154. 31) vs. (1845.33 ± 126.88)] were increased after fluoxetine administration in rats with depression (P<0. 01). (3) Fluoxetine increased mRNA expressions of Notch1 signaling components [NICD mRNA (0. 23 ±0. 01) vs. (0. 10 ±0.01), Hes1 mRNA (0. 56 ±0.04) vs. (0. 28 ±0.02), Hes5 mRNA (0. 24 ±0.02) vs. (0.10 ±0.02), Jag1 mRNA (0.82 ±0.06) vs. (0.56 ±0.03)] in the rat hippocampus compared with the CUMS group (P<0. 01 or P<0. 001). Fluoxetine enhanced protein levels of Notch1 signaling components [NICD(1.99 ±0.07) vs. (0.53 ±0.10), Hes5(0. 64 ±0. 04) vs. (0.37 ±0.09),Jag1 (2. 34 ± 0. 13) vs. (0. 68 ± 0. 17)] in the rat hippocampus compared with the CUMS group (P <0.01). Conclusion The up-regulation of the Notch1 pathway with chronic fluoxetine administration might partly contribute to increased neurogenesis in the rat hippocampus with depression.     

下丘脑NK2受体在应激介导抑郁症发生中的作用

目的 阐明神经激肽A的受体NK2在慢性不可预见性温和刺激(CUMS)所致的抑郁样行为发生、发展中的可能作用和机制.方法 SD大鼠随机分为对照组、氟西汀组和抑郁模型组3组,行为学检测后,氟西汀组和抑郁模型组均给予孤养+CUMS造成大鼠抑郁症模型,再次行为学检测后,氟西汀组大鼠给予氟西汀腹腔注射21d,抑郁模型组给予同体积生理盐水腹腔注射21d,再次进行行为学检测,麻醉后取大鼠下丘脑,提取组织mRNA和蛋白后,采用荧光定量PCR技术和Western Blot技术检测NK2的表达.结果 应激前3组大鼠的糖水偏好率和强迫游泳的不动时间均无统计学意义.应激后,氟西汀组和抑郁模型组大鼠的糖水摄入明显减少、强迫游泳不动时间明显增长,差异均有统计学意义(P＜0.05).而给予氟西汀后,氟西汀组大鼠的糖水偏好率有所增加,强迫游泳的不动时间有所减少,与对照组比较差异无统计学意义(P＞0.05),但与抑郁组大鼠相比,差异均有统计学意义(P＜0.05).与对照组和氟西汀组比较,抑郁组下丘脑NK2受体的mRNA和蛋白的表达量明显升高,差异有统计学意义(P＜0.05),而氟西汀组与对照组相比差异无统计学意义(P＞0.05).结论 CUMS可引起大鼠行为学改变,造成大鼠抑郁模型;NK2受体的mRNA和蛋白的表达量在应激后大鼠的下丘脑中明显升高,经氟西汀干预后可恢复到正常水平,说明NK2受体与抑郁症的发生、发展过程具有相关性,在抑郁症的发病机制中可能发挥重要作用.     

Effects of ginsenoside on brain-derived neurotrophic factor and tyrosine kinase B mRNA expression in the hippocampal formation of aged rats*☆

BACKGROUND： There are a limited number of studies involving the effects of ginsenosides, the active component of ginseng, on expression of hippocampal TrkB mRNA in aged rats.
OBJECTIVE： To observe expression of brain-derived neurotrophic factor （BDNF） and tyrosine kinase B （TrkB） mRNA in the hippocampal formation of aged rats, as well as changes after ginsenoside administrated.
DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed at the Department of Anatomy, College of Basic Medical Sciences, China Medical University in March 2005.
MATERIALS： A total of 39 female, Wistar rats were randomly divided into 3 groups （n = 13 each）： young （3-5 months old）, aged （27 months old）, and ginsenoside group （received 25mg/kg/d ginsenoside in the drinking water between 17 and 27 months of age）.
METHODS： Following anesthesia, the rats were exsanguinated and perfused transcardially with chilled, heparinized, 0.9% saline. The brains were removed and post-fixed in 40 g/L paraformaldehyde/phosphate buffer for 20 minutes, and further incubated in 30% sucrose/phosphate buffer overnight.
MAIN OUTCOME MEASURES： In situ hybridization, immunohistochemistry, and image analysis were used to investigate expression of BDNF and TrkB mRNA in the hippocampal formation. RESULTS： The expression levels of BDNF in the hippocampal CA3 and CA1 of aged rats was significantly less than the young group （t = 2.879, 1.814, 1.984, P 〈 0.05）. BDNF expression was significantly greater in the dentate gyrus of the ginsenoside group, compared with the aging group （t = 1.943, P 〈 0.01）. The expression of TrkB mRNA in the hippocampal CA3, CA1, and dentate gyrus of aged rats was less than the young group （t = 3.540, 3.629, 17.905, P 〈 0.01）. TrkB mRNA expression in the CA3 region and dentate gyrus of the ginsenoside group was significantly greater compared with the aging group （t = 1.293, 3.386, P 〈 0.05, 0.01 ）.
CONCLUSION： BDNF and TrkB mRNA expression in the hipp