缬草对慢性应激导致的抑郁大鼠大脑海马p-CREB阳性神经元数量的影响

目的探讨最佳剂量缬草对慢性应激导致的抑郁大鼠行为及其大脑海马磷酸化cAMP反应元件结合蛋白(phosphorylated cAMP responsive element-binding protein,p-CREB))阳性神经元的影响。方法将35只大鼠随机均分为正常对照组、未用药模型组、阴性对照模型组、阳性对照模型组、低剂量缬草模型组、中剂量缬草模型组和高剂量缬草模型组。在用药期间,每周测试大鼠体质量、自来水及1%糖水摄取量1次。用药后,计数大脑海马神经元数量,确定缬草最佳剂量。然后根据前述方法,在灌药结束后灌注和固定所有大鼠。采用中性红染色、免疫组化等方法对大鼠海马p-CREB和脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)阳性神经元进行检测。结果高剂量(100mg·kg-1·d-1)缬草能促使抑郁大鼠1%糖水摄取量恢复至正常水平,还可使抑郁大鼠大脑海马神经元以及p-CREB阳性神经元数量恢复到正常水平。正常对照组大鼠大脑海马神经元的BDNF染色较浅淡,其余各组大鼠大脑海马神经元的BDNF阳性染色没有明显差异。结论本研究高剂量(100mg·kg-1·d-1)缬草可能是治疗慢性应激导致大鼠抑郁症的最佳剂量。缬草可以改善抑郁大鼠的行为活动,恢复大脑海马神经元以及p-CREB阳性神经元数量到正常水平。     

慢性应激对心肌梗死后大鼠模型行为学及海马BDNF的影响

目的:探讨慢性应激对心肌梗死后大鼠模型行为学及海马BDNF的影响.方法:建立急性心肌梗死模型.结合慢性不可预见的轻度应激和孤养制作心梗并抑郁复合大鼠模型.观察动物的体重变化和行为学指标,用Westernblot方法检测海马BDNF蛋白表达.结果:经过21天慢性不可预见轻度应激.模型组大鼠体重、糖水消耗和糖水偏爱百分比、敞箱试验得分均明显降低,纯水消耗显著增加;海马BDNF蛋白表达减少(P<0.05).结论:对急性心肌梗死大鼠采用21天慢性应激后,模型鼠体重下降、行为学明显异常,符合抑郁动物的行为学改变,且存在海马神经元可塑性降低的表现,这可能是心肌梗死并抑郁发病的机制之一.     

慢性应激对大鼠空间学习记忆和海马一氧化氮的影响

目的 :探讨慢性应激对大鼠空间学习记忆和海马NO的影响。方法 :采用电击足底结合噪声建立慢性应激大鼠模型 ,Morris水迷宫观察动物的学习和记忆能力 ,同时检测海马NO含量和NOS活性。结果 :慢性应激大鼠在Morris水迷宫的空间学习和记忆能力明显下降 ,海马NO含量和NOS活性 (3 87± 0 47nmol/mgpro和 10 2 64± 13 33pmol/mgpro/min)显著高于对照组大鼠 (2 76± 0 43nmol/mgpro和 78 2 5± 10 67pmol/mgpro/min)。结论 :慢性应激损害大鼠空间学习和记忆能力 ,可能与其海马内NO增多有关     

慢性轻度不可预见性应激对大鼠海马内甘丙肽表达的影响

目的:观察慢性轻度不可预见性应激(chronic unpredictable mild stress,CUMS)对大鼠海马甘丙肽(ga-lanin,Gal)蛋白及mRNA表达的影响,探讨Gal在大鼠实验性抑郁症发病过程中的作用机制。方法:将20只健康雄性SD大鼠,随机分为正常组和模型组,每组10只。孤养结合CUMS 21 d建造抑郁症模型,应用旷场试验和糖水偏好试验检测大鼠行为学变化,使用免疫荧光组织化学方法和逆转录多聚酶链反应(RT-PCR)法测定Gal及Gal mRNA的表达。结果:造模后模型组大鼠运动总路程、中央路程、周边路程及糖水摄入量均较正常组偏低(P<0.05);模型组与正常组相比,海马内Gal及Gal mRNA的表达同样降低(P<0.05)。结论:慢性轻度不可预见性应激可使大鼠海马内Gal及Gal mRNA的表达量下降,推测Gal在抑郁发病过程中可能起到神经保护作用。     

慢性应激对大鼠海马Bcl-xl表达的影响及应激后的变化

目的:探讨慢性应激对大鼠海马神经元Bcl-xl蛋白表达的影响及其应激后的变化。方法:采用慢性强迫冰水游泳制作动物模型。运用open-field法观察大鼠行为学的变化,运用免疫组织化学方法观察大鼠海马DG区、CA3区Bcl-xl的变化。结果:与对照组相比,实验组1大鼠海马CA3区齿状回(DG)区Bcl-xl平均灰度值显著增加(t=4.69,P<0.05和t=3.77,P<0.01),实验组2平均灰度值与对照组2相比同样增加(t=3.35,P<0.05和t=3.30,P<0.05)。结论:慢性应激使大鼠海马Bcl-xl表达降低,应激三十天后,其表达仍低于对照组。     

慢性复合应激对成年大鼠海马NeuroD表达的影响

本实验通过观察慢性复合应激对成年大鼠海马NeuroD表达的影响,探讨慢性复合应激与海马神经发生的关系。将成年雄性大鼠32只随机分为慢性复合应激组(简称应激组)和正常对照组(简称对照组)。应激组动物每天不规律交替暴露于四种复合应激原中,共持续6周。然后运用免疫组织化学染色、Western-blot和RT-PCR技术分别观察海马内NeuroD阳性神经元数量、NeuroD蛋白水平和核酸水平的变化。结果显示:慢性复合应激组动物海马齿状回NeuroD阳性神经元数量明显增多(P<0.05);海马NeuroD蛋白的表达明显增强(P<0.05);海马NeuroD mRNA水平明显上调(P<0.05)。表明慢性复合应激可引起海马NeuroD阳性神经元数量增多和NeuroD表达水平升高,提示慢性复合应激可能促进大鼠海马的神经发生。     

慢性应激致大鼠抑郁行为涉及海马形态变化和BDNF表达降低

目的 研究慢性不可预见轻度刺激(CUMS)致大鼠抑郁模型与海马病理形态改变和脑源性神经营养因子(BDNF)表达异常的关系.方法 大鼠分为对照组和模型组,应用CUMS建立大鼠抑郁模型;以开场(open-field)法、黄嘌呤氧化法和硫代巴比妥酸法、HE染色和免疫组化法分别检测大鼠行为、皮质MDA水平和SOD活力、海马病理形态和海马BDNF表达.结果 与对照大鼠相比,接受28 d CUMS大鼠开场实验得分明显降低,皮质SOD活力显著下降和MDA含量明显增高,海马神经元呈明显核固缩和BDNF表达显著降低(吸光度值803±422vs237±96,P<0.01).结论 CUMS致大鼠明显抑郁行为,其机制可能与神经元氧化-抗氧化系统失衡,自由基生成增加,由此致海马神经元受损和BDNF表达减少有关.     

慢性复合应激对大鼠海马生长休止蛋白7表达的影响

目的 探讨慢性复合应激对大鼠海马神经元中生长休止蛋白7(Gas7)的表达变化及意义.方法 36只大鼠随机分为慢性复合应激组和正常对照组.复合应激组动物进行6周的垂直旋转、睡眠剥夺、捆绑(6h/d)和夜间光照等慢性复合性应激试验;实验结束后,所有动物采用免疫组织化学和免疫印迹等方法 检测大鼠海马Gas7蛋白表达的变化和神经元凋亡情况.结果 Gas7在对照组和实验组大鼠海马各区均有表达,主要表达在海马神经元的胞质和突起内.其中在CA1区和齿状回呈较强阳性表达,CA3区表达则较弱;慢性复合应激组CA1区和齿状回阳性染色加深,平均吸光度明显上升(P<0.05),而CA3区则不明显(P>0.05).慢性复合应激组中部分切片在下托可见少量Caspase-3免疫反应阳性细胞.免疫印迹检测表明,慢性复合应激组大鼠海马Gas7表达明显增强,与正常对照组相比,差异具有显著性(P<0.05).结论 Gas7可能参与了在应激情况对神经元的保护作用,以及促进神经元的发生和发育.     

复方刺蒺藜苷对慢性应激抑郁模型大鼠行为学及海马CNTF表达的影响

目的：观察刺蒺藜苷对慢性应激抑郁大鼠行为学及海马CNTF表达的影响.方法：将大鼠随机分为正常组、模型组、复方刺蒺藜苷组、氟西汀组,采用慢性轻度不可预见性应激配合孤养复制抑郁模型.通过敞箱实验观察抑郁模型大鼠行为学改变并运用免疫组化和原位杂交方法探讨复方刺蒺藜苷对抑郁模型大鼠海马神经元细胞CNTF、CNTFmRNA表达的影响.结果：慢性应激抑郁大鼠敞箱实验中水平穿越格数、竖立次数、理毛时间有减少,中央格停留时间、粪便粒数均有增加.刺蒺藜苷和氟西汀可改善大鼠行为学变化.与模型组相比,复方刺蒺藜苷组大鼠海马神经元CNTF免疫反应阳性颗粒数目增多,神经元平均灰度值降低.结论：刺蒺藜苷能明显改善抑郁动物的各项行为学指标,增加海马CNTF、CNTF mRNA的表达具有抗抑郁作用.     

Acupuncture inhibits NLRP3 inflammasome activation in the prefrontal cortex of a chronic stress rat model of depression

The Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-driven inflammatory response plays a key role in the pathophysiology of depression. Mounting evidence suggests that acupuncture is an effective treatment for depression. In this study, we investigated the effects of acupuncture treatment at the acupoints Baihui (GV20) and Yintang (GV29) on NLRP3 inflammasome in the prefrontal cortex (PFC) of an animal model of depression. Rats that underwent chronic unpredictable mild stress (CUMS) for 6 weeks showed depressive-like behaviors, which were confirmed by sucrose preference and locomotor activity in the open field test. The protein levels of NLRP3, apoptotic speck-containing protein with a card (ASC), and cysteinyl aspartate specific proteinase-1 (Caspase-1) in the PFC were detected by Western blot analysis. The mRNA and protein expressions of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in the PFC were measured by the real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Our results showed that the depressive-like behaviors in stressed rats were reversed by acupuncture treatment. Compared with control rats, the protein expression of NLRP3, ASC, and Caspase-1 and the mRNA and protein expressions of IL-1β and IL-18 in the PFC were markedly increased in CUMS rats. Acupuncture treatment significantly decreased the levels of NLRP3 inflammasome components and inflammatory cytokines in the PFC. Acupuncture treatment also reduced the number of TUNEL-positive cells in the PFC. These results suggested that acupuncture has antidepressant-like effects, and its mechanism appears to be involved in the inhibition of NLRP3 inflammasome activation and apoptosis in the PFC.     

Effects of neonatal flutamide treatment on hippocampal neurogenesis and synaptogenesis correlate with depression-like behaviors in preadolescent male rats

The prevalence of major depressive disorder (MDD) in adult men is roughly half that of women. Clinical evidence supports a protective effect of androgens against depressive disorders in men. The developing brain is subject to androgen exposure but a potential role for this in depression during adulthood has not been considered. In order to explore this question we treated newborn male rat pups with the androgen receptor antagonist flutamide to block endogenous androgen action and then conducted behavioral tests prior to puberty. Depression-like behaviors were assessed with the Forced Swim Test (FST) and the Sucrose Preference Test (SPT), and anxiety-like behaviors were assessed with the Open Field Test (OFT) and the Novelty-Suppressed Feeding Test (NSFT). Compared to the vehicle-treated controls, neonatal-flutamide treatment caused a significant increase in depression-like behaviors in preadolescent male rats but did not cause any significant difference in anxiety-like behaviors. In separate experiments, male pups with and without flutamide treatment were injected with 5-bromo-2′-deoxyuridine-5′-monophosphate (BrdU) from postnatal day (PND) 1 to 4 to label newly produced cells or the hippocampi were Golgi-Cox imbedded and pyramidal neurons visualized. Three lines of evidence indicate neonatal flutamide treatment inhibits hippocampal neurogenesis and neuronal dendritic spine formation in preadolescent male rats. Compared to vehicle controls, flutamide treatment significantly decreased (1) the number of microtubal associated protein-2+ (MAP-2) neurons in the CA1 region, (2) the number of MAP-2+ neurons in the dentate gyrus (DG) region of the hippocampus, and (3) the density of dendritic spines of pyramidal neurons in the CA1 region. However, there was no effect of flutamide treatment on the number of glial fibrillary acidic protein (GFAP)+ or GFAP+/BrdU+ cells in the hippocampus. This study suggests that the organizational effect of androgen-induced hippocampal neurogenesis is antidepressant.     

GSK650394对慢性应激抑郁症模型大鼠行为及海马神经营养的调节作用

目的探讨血清和糖皮质激素调节蛋白激酶1(SGK1)抑制剂GSK650394对抑郁症模型大鼠抑郁样行为及海马神经营养的调节作用。方法将SD大鼠随机分为对照组、抑郁模型(慢性温和不可预见性应激加孤养)组、GSK650394(2.8 g/L,按1 mL/kg腹腔注射)干预组;采用强迫游泳、糖水消耗、Morris水迷宫实验观察模型动物的情绪行为变化;用ELISA检测大鼠海马血浆和血清中皮质酮(CORT)、5-羟色胺(5-HT)、去甲肾上腺素(NE)含量;用Western blot检测海马中脑源性神经营养因子(BDNF)、神经营养素3(NT-3)、神经生长因子(NGF)的表达。结果与对照组比较,模型组大鼠蔗糖水偏食度显著降低、游泳不动时间增加(P<0.01)、逃避潜伏期(EL)、目标象限的潜伏时间(Lat.T)均显著延长(P<0.05或P<0.01);血浆CORT显著升高(P<0.01)、血清5-HT、NE和海马NT-3、BDNF、NGF表达显著降低(P<0.05或P<0.01)。与模型组比较,GSK650394可显著增加蔗糖水偏食度、降低游泳不动时间(P&l...     

皮质酮与慢性不可预见性应激诱导的两种抑郁症模型比较

目的从行为学及分子水平比较皮质酮(CORT)与慢性不可预见性应激(CUMS)诱导的抑郁症模型的异同,为抑郁症发病机制研究及抗抑郁药物的筛选与评价模型提供一定的参考。方法将30只雄性C57BL/6小鼠随机分成对照组(Ctrl)、慢性不可预见应激组(CUMS)和皮质酮注射应激组(CORT)组,制作应激模型21d,期间每3d对小鼠进行称重。21d模型制作结束后,对小鼠进行行为学测试,并于第22天,通过眼眶取血收集动物血清,并用ELISA法测定血清皮质酮含量。眼眶取血后脱颈椎处死动物,取出动物的胸腺和脾脏进行称重,计算脏器指数;取出脑组织,置于液氮罐保存,尼氏(Nissl)染色法观察小鼠大脑海马区神经元损伤情况;采用Western blotting、RT-PCR方法测定抑郁症相关蛋白及基因的表达。结果与对照组相比,两种抑郁症模型组开场实验中的行为学指标均改变,强迫游泳和悬尾实验的累积不动时间显著升高。两个模型组的胸腺指数无明显变化,而CORT组的脾脏指数较对照组下降。CUMS和CORT组小鼠血清皮质酮含量高于对照组,CORT组与CUMS组相比有升高趋势,但差异无显著性。CUMS和CORT两种模型均使海马CA1、CA3和DG区神经元密度降低,CORT模型变化更明显。两模型组的促肾上腺素释放激素(CRH)的mRNA和蛋白的表达量均显著性增加,脑源性神经营养因子(BDNF)、磷酸化转录因子环磷腺苷反应元件结合蛋白(p-CREB)和磷酸化细胞外信号调节激酶(p-ERK)的蛋白表达水平均呈现明显地抑制,但CUMS和CORT两组之间差异无显著性。结论 CORT模型和CUMS模型均能成功构建抑郁症模型,且与下丘脑-垂体-肾上腺(HPA)轴紊乱有关,两种模型在小鼠海马结构改变及大脑BDNF-pCREB和ERK信号通路激活等方面差异无显著性。提示,CORT模型可用于抑郁症机制的研究及抗抑郁药的筛选与评价,尤其可用于以HPA轴功能紊乱所引起的抑郁症分子机制探讨。     

Rapid eye movement sleep deprivation contributes to reduction of neurogenesis in the hippocampal dentate gyrus of the adult rat

Study Objectives:

The dentate gyrus (DG) of the adult hippocampus contains progenitor cells, which have potential to differentiate into neurons. Previously we reported that 96 hours of total sleep deprivation reduces neurogenesis in the DG of adult rats. Loss of either non-rapid eye movement (NREM) or rapid eye movement (REM) sleep could have contributed to the effect of total sleep deprivation. The present study assessed the effect of 4 days of REM sleep deprivation (REMD) on neurogenesis.

Design:

REMD was achieved by brief treadmill movement initiated by automatic online detection of REM sleep. A yoked-control (YC) rat was placed in the same treadmill and experienced the identical movement regardless the stage of the sleep-wake cycle. The thymidine analog 5- bromo- 2′- deoxy-uridine and the intrinsic proliferation marker, Ki-67, were both used to label proliferating cells.

Setting:

Basic neurophysiology laboratory.

Participants:

Male Sprague-Dawley male rats (300 – 320 g)

Results:

REM sleep was reduced by 85% in REMD rats and by 43% in YC, compared with cage control animals and by 79% in REMD rats compared with YC. NREM sleep and slow wave activity within NREM did not differ in REMD and YC groups. Cell proliferation was reduced by 63 % in REMD compared with YC rats, and by 82% and 51%, respectively, in REMD and YC rats compared with cage controls. Across all animals, cell proliferation exhibited a positive correlation with the percentage of REM sleep (r = 0.84, P < 0.001). Reduced cell proliferation in REMD rats was confirmed with the intrinsic proliferation marker, Ki-67. REMD also reduced the percentage of proliferating cells that later expressed a mature neuronal marker.

Conclusions:

The present findings support a hypothesis that REM sleep-associated processes facilitate proliferation of granule cells in the adult hippocampal DG.

Citation:

Guzman-Marin R; Suntsova N; Bashir T; Nienhuis R; Szymusiak R; McGinty D. Rapid eye movement sleep deprivation contributes to reduction of neurogenesis in the hippocampal dentate gyrus of the adult rat. SLEEP 2008;31(2):167–175.     

跑台运动及周龄对大鼠海马神经发生的影响

目的探讨运动及其周龄对大鼠海马神经发生的影响。方法将40只雄性SD大鼠随机分为7周龄安静对照组、7周龄小强度运动组、9周龄安静对照组和9周龄小强度运动组。腹腔注射BrdU于大鼠,持续注射6d。采用免疫组织荧光染色技术,检测各组大鼠海马齿状回内新生细胞和新生神经元数量。结果各组动物海马齿状回BrdU免疫阳性(BrdU+)细胞数目为:7周龄安静对照组50.66±10.54,7周龄小强度运动组74.21±17.00,9周龄安静对照组37.62±9.02,9周龄小强度运动组46.01±10.82。各组动物海马齿状回BrdU++NeuN+细胞数目为:7周龄安静对照组22.54±6.76,7周龄小强度运动组33.38±8.26,9周龄安静对照组15.26±4.42,9周龄小强度运动组17.61±3.86。结论运动促进海马齿状回神经发生,随着周龄的增长而减弱。     

Adult neurogenesis is reduced in the dorsal hippocampus of rats displaying learned helplessness behavior

Clinical and preclinical studies suggest that the hippocampus has a role in the pathophysiology of major depression. In the learned helplessness (LH) animal model of depression after inescapable shocks (ISs) animals that display LH behavior have reduced cell proliferation in the hippocampus; this effect can be reversed by antidepressant treatment. Using this model, we compared rats that displayed LH behavior and rats that did not show LH behavior (NoLH) after ISs to determine whether reduced hippocampal cell proliferation is associated with the manifestation of LH behavior or is a general response to stress. Specifically, we examined cell proliferation, neurogenesis, and synaptic function in dorsal and ventral hippocampus of LH and NoLH animals and control rats that were not shocked. The LH rats had showed reduced cell proliferation, neurogenesis, and synaptic transmission in the dorsal hippocampus, whereas no changes were seen in the ventral hippocampus. These changes were not observed in the NoLH animals. In a group of NoLH rats that received the same amount of electrical shock as the LH rats to control for the unequal shocks received in these two groups, we observed changes in Ki-67⁺ cells associated with acute stress. We conclude that reduced hippocampal cell proliferation and neurogenesis are associated with the manifestation of LH behavior and that the dorsal hippocampus is the most affected area.     

腹外侧眶皮层中miR-200对慢性应激所致大鼠抑郁行为调控作用研究

目的:观察慢性不可预知温和应激(CUMS)模型大鼠腹外侧眶皮层(VLO)内miR-200和双特异性磷酸酶1(DUSP1)表达变化,并探讨VLO内注射miR-200模拟物对抑郁行为的调控作用及机制。方法:大鼠建立CUMS抑郁模型后分为5组:CUMS+miR-200模拟物组(VLO内注射20 pmol miR-200 mimic);CUMS+阴性对照组(VLO内注射20 pmol阴性对照siRNA);无应激+阴性对照组;无应激+miR-200模拟物组;CUMS+氟西汀(10 mg/kg/d)组。依次进行蔗糖偏爱测试、旷场实验、高架十字迷宫实验。Western Blot检测VLO内DUSP1、细胞外调节蛋白激酶(ERK)、pERK蛋白表达。结果:与无应激组比较,CUMS组大鼠体重降低(P0.0001)、蔗糖偏爱下降(P=0.008),VLO中miR-200表达减少(P0.0001),DUSP1表达增高(P=0.0054);与CUMS+阴性对照组比较,CUMS+miR-200模拟物组大鼠蔗糖偏爱率(P=0.028),开放臂进入时间(P=0.031)和进入次数(P0.0001)均升高,总活动距离不受影响;与CUMS+阴性对照组比较,CUMS+miR-200模拟物组VLO中DUSP1(P=0.046)和pERK(P=0.042)蛋白水平显著升高。结论:慢性应激性环境所致抑郁样行为与VLO内pERK下调有关,miR-200可直接下调VLO内DUSP1表达,提高pERK表达并最终改善抑郁症状。