氟西汀对CUS大鼠抑郁样行为及海马内源性大麻素相关基因表达的调节作用

目的:探讨内源性大麻素1型受体(Cannabinoid receptor1,CB1R)、二酰基甘油脂肪酶(Diacylglycerol lipase alpha,DAGLα)和单酰甘油脂肪酶(Monoacylglycerol,MAGL)在氟西汀(Fluoxetine)改善慢性不可预见应激(Chronic unpredictable stress,CUS)大鼠抑郁样行为中的作用。方法:在本研究中,给予暴露于慢性不可预测应激(CUS)的大鼠腹腔注射氟西汀(10 mg/kg)或生理盐水治疗14天,最后一次腹腔注射结束24小时后评估抑郁样行为以及海马中CB1R,DAGLα和MAGL的表达。此外,通过注射慢病毒下调大鼠海马中CB1R和DAGLα的表达。病毒注射两周后,所有大鼠接受CUS刺激,然后腹腔注射10 mg/kg氟西汀或生理盐水14天。给药结束24小时后进行行为学及分子生物学检测。结果:(1)CUS组大鼠具有明显的抑郁样行为,包括旷场中心活动时间减少(P0.05),糖水摄取量下降(P0.05),强迫游泳不动时间增加(P0.01);氟西汀治疗可以缓解CUS大鼠的抑郁行为,与CUS组相比较,CUS+Flx组大鼠的糖水偏好和旷场中心活动时间增加(P0.05,P0.05),强迫游泳不动时间减少(P0.05);(2)CUS组大鼠海马的CB1R、DAGLα的表达下调(P0.05),MAGL的表达上调(P0.05);氟西汀上调CUS大鼠海马的CB1R和DAGLα表达(P 0.05),下调了MAGL表达(P0.05);(3)病毒干预下调海马区的CB1R或DAGLα后,抑制了氟西汀的抗抑郁作用。结论:氟西汀可以通过调节CUS大鼠海马的内源性大麻素相关基因表达改善CUS大鼠的抑郁行为,发挥抗抑郁作用。     

天麻素对脑缺血再灌注小鼠海马新生神经元的保护作用

目的:探讨不同剂量天麻素(Gastrodin,GAS)对缺血再灌注模型小鼠海马新生神经元的保护作用及其可能机制。方法:将50只C57BL/6小鼠随机分为假手术组(Sham)、模型组(MCAO+Vehicle)、模型+天麻素低剂量(10 mg/kg)组(MCAO+GAS(L)),模型+天麻素中剂量(50 mg/kg)组(MCAO+GAS(M)),模型+天麻素高剂量(100 mg/kg)组(MCAO+GAS(H))。除Sham组接受假手术外(皮肤切开,分离颈动脉),分别对MCAO组及MCAO+GAS各组行右侧颈内动脉栓线术,造成并保持大脑中动脉闭塞(MCAO)1 h。术后,Sham组和MCAO组即刻腹腔注射生理盐水(0.1 m L/kg),MCAO+GAS各组注射不同剂量天麻素,每24小时重复给药1次,连续7天。最后一次注射24 h后,对各组小鼠的神经功能进行评分,之后处死动物取脑组织,通过HE、免疫荧光染色以及Western Blot观察和比较各组小鼠海马形态学和DCX的表达水平。结果:(1)术后第7天,MCAO+Vehicle组小鼠神经功能评分(3.2±0.63)显著高于假手术组、MCAO+GAS(M)(1.8±0.63)和MCAO+GAS(H)组(P0.05)。(2)术后第7天,与假手术组相比较,MCAO+vehicle组海马颗粒细胞排列不规则,核稍大且固缩深染,齿状回部有较多空洞;与MCAO+vehicle组比较,MCAO+GAS(H)组海马空洞样改变减少,细胞排列较整齐,胞膜较完整,核结构较清晰。(3)术后第7天,与假手术组相比较,DCX染色阳性细胞数显著减少,而MCAO+GAS(M)组DCX染色阳性细胞数(183±64.5)和MCAO+GAS(H)组DCX染色阳性细胞数(195±93.68)显著高于MCAO+Vehicle组。MCAO+Vehicle组海马的DCX表达水平显著低于假手术组及MCAO+GAS(M)组和GAS(H)组(P0.01)。结论:天麻素可能通过上调海马DCX的表达水平,调节海马神经发生,进而对缺血性脑卒中后再灌注发挥神经保护作用。     

调控RET依赖性GDNF信号通路对大鼠癫痫模型的影响

目的:探究双侧海马CA1区立体定向注射anti-GDNF抗体对匹鲁卡品诱导的大鼠癫痫模型的影响。方法:选择成年雄性SD大鼠60只,并随机分为3组,即假手术组(sham组,n=20)、癫痫模型组(model组,n=20)和GDNF抑制剂组(anti-GDNF组,n=20)。使用氯化锂-匹鲁卡品腹腔注射诱导癫痫模型,sham组只给予氯化锂,anti-GDNF组在造模前2 h给予大鼠双侧海马CA1区立体定向注射anti-GDNF抗体。在造模后1、3、7 d观察大鼠癫痫的发作频率,7 d后采用脑电图监测(EEG)测定脑电波的变化情况,通过免疫组化方法测定海马CA1区域神经元数量变化(Neu N表达水平),造模后1 d时使用western blot方法测定海马CA1区GDNF、RET和P53蛋白的表达。结果:Model组大鼠棘-慢波数量明显高于Sham组,anti-GDNF组以上指标较model组显著减少(P0.05);Model组海马CA1区神经元大量凋亡,但anti-GDNF组凋亡较model组显著减少(P0.05)。与Sham组比较,在癫痫发作后1 d,model组的GDNF、RET表达水平上调,P53表达水平下降(P0.05),而anti-GDNF组大鼠海马CA1区GDNF、RET表达较model组明显下调,P53表达水平显著上降(P0.05)。结论:双侧海马CA1区立体定向注射anti-GDNF抗体能够减少癫痫发作,并对海马神经元起到保护作用,可能与其抑制GDNF/RET/P53信号通路有关。     

高压氧预处理对大鼠脑缺血再灌注损伤的保护作用及对其海马BDNF和GDNF基因表达的影响

目的:探讨高压氧预处理(Hyperbaric oxygen preconditioning, HBO-PC)对大鼠脑缺血再灌注损伤的保护作用及对其海马脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)、胶质细胞源性神经营养因子(glialcellline-derivedneurotrophicfactor,GDNF)基因表达的影响。方法:将32只SD雄性大鼠随机分为对照组(Sham组)、高压氧对照组(HBO组)、模型组(MCAO组)、高压氧预处理+模型组(HBO+MCAO组),对HBO组和HBO+MCAO组连续给予高压氧预处理5天,随后对MCAO组和HBO+MCAO组进行右侧颈内动脉栓线术,建立大脑中动脉闭塞(middle cerebral artery occlusion, MCAO)模型,其他两组行假手术,于术后第7天对各组大鼠进行Morris水迷宫行为学检测和神经功能评分,检测结束后处死大鼠,进行神经功能缺损评分及氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride, TTC)染色;通过蛋白免疫印迹法(Western Blot)检测大鼠海马组织BDNF和GDNF的基因表达情况。结果:(1)神经功能评分提示:Sham组和HBO组均未出现神经功能障碍,MCAO组大鼠出现明显的神经功能障碍,MCAO+HBO组神经功能评分明显高于MCAO组(P0.05)。(2)TTC检测提示:Sham组和HBO组脑组织损伤一侧均未出现梗死灶,MCAO组出现较大的梗死面积比(25.45±8.75)%,MCAO+HBO组的梗死面积比(18.84±10.55)显著小于MCAO组,差异具有统计学意义(P 0.05)。(3)Western Blot检测显示:MCAO组BDNF与GDNF基因表达水平显著低于Sham组和HBO组,差异具有统计学意义(P 0.05),而MCAO+HBO组可以逆转这一效应,差异具有统计学意义(P 0.05)。结论:高压氧预处理可以通过调节BDNF、GDNF基因表达,改善MCAO模型大鼠神经功能和认知水平,发挥神经保护作用。     

焦虑性抑郁模型大鼠脑区单胺递质含量与神经因子表达的变化

目的研究焦虑性抑郁模型大鼠海马、杏仁核、前额叶皮质内单胺递质的含量变化及脑内神经营养因子的表达趋势,探讨其可能的发病机制。方法 60只SD大鼠随机分为正常对照组、溶媒对照组、焦虑模型组、抑郁模型组、焦虑性抑郁模型组,每组12只。采用慢性束缚应激联合皮质酮注射的方法建立焦虑性抑郁大鼠模型,造模时间为21 d,造模结束后采用高架十字迷宫测试,旷场实验,强迫游泳实验评价大鼠的焦虑和抑郁样行为,HPLC-ECD法检测大鼠海马、杏仁核、前额叶皮质的单胺递质5-HT、NE、DA含量,蛋白印迹法检测大鼠各脑区神经营养因子BDNF、NT-3的含量。结果焦虑性抑郁模型组大鼠在进入开臂的时间、次数、旷场中自主活动次数均与焦虑组相当,与对照组及抑郁组比较差异有显著性(P0.01或P0.05),在强迫游泳中的不动时间显著增加,与对照组及焦虑组对比差异有显著性(P0.01);同时,与对照组比较,焦虑性抑郁模型组大鼠海马5-HT、杏仁核及前额叶皮质区的5-HT和NE含量均显著下降(P0.01或P0.05);此外,与对照组比较,焦虑性抑郁模型组大鼠各脑区BDNF、NT-3含量显著下降(P0.01或P0.05),同时与焦虑组比较,BDNF含量显著下降(P0.05)。结论焦虑性抑郁模型组大鼠具有显著的焦虑及抑郁样行为,其发病机制可能与脑内海马、杏仁核、前额叶皮质区域的单胺递质含量降低及神经营养因子BDNF、NT-3表达下调有关。     

电针预处理对PTSD模型大鼠焦虑样行为及海马Sirt1/MAO-A基因表达的影响

目的:探讨电针预处理对创伤后应激障碍大鼠(PTSD)焦虑样行为的改善作用及对海马去乙酰化酶Sirt1及单胺氧化酶MAO-A基因表达的影响。方法:将32只SD大鼠随机分为对照组(Sham),模型组(PTSD),电针刺激组(EA),电针预处理+模型(EA+PTSD),每组8只。电针刺激组(EA)和电针预处理+模型(EA+PTSD)组大鼠每天给予百会穴电针刺激(2/15 Hz,1 m A)30 min,连续刺激7 d。然后对模型组(PTSD)组和电针预处理+模型(EA+PTSD)组大鼠进行ESPS造模处理。造模结束14天后,通过旷场和高架十字测试其焦虑样行为,随后处死大鼠,通过实时定量PCR(RT-PCR)检测海马Sirt1和MAO-A的m RNA表达情况。结果:(1)PTSD大鼠具有明显的焦虑样行为,包括旷场中心的探索减少(44.94±13.66,16.86±7.12,P0.05)和高架十字开臂运动时间减少(55.90±26.39,23.36±12.23,P0.01),PTSD组大鼠海马Sirt1和MAO-A的m RNA表达增加(1.00±0.07,1.90±0.05;1.01±0.10,1.54±0.15,P0.01)。(2)电针预处理可以缓解PTSD大鼠的焦虑样行为,PTSD与EA+PTSD组之间存在显著性差异(16.86±7.12,36.24±13.28,P0.05;23.36±12.23,50.14±20.77,P0.05)。(3)电针预处理可以抑制PTSD大鼠海马的Sirt1和MAO-A m RNA表达,PTSD与EA+PTSD组之间的Sirt1和MAO-A的m RNA水平存在显著性差异(1.90±0.05,1.30±0.08,P0.05;1.54±0.15,1.23±0.15,P0.05)。结论:电针预处理可以调节PTSD大鼠海马的Sirt1和MAO-A的m RNA水平,缓解PTSD大鼠的焦虑样行为。     

CFA注射致炎性疼痛过程中海马内BDNF的表达及作用研究

目的:探索完全弗氏佐剂(Complete Freund’s Adjuvant,CFA)致炎性疼痛后大鼠海马内脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)表达的变化及其作用。方法:雄性SD大鼠随机分为溶媒对照组和实验组,实验组大鼠左侧足底皮下注射CFA和生理盐水混合溶剂100μL,建立炎性疼痛模型,注射后大鼠分别存活1天、4天、7天、14天(n=20只/组)。在建模前和建模后不同时间点采用Von Frey纤维检测大鼠50%机械缩足阈值(paw withdrawal threshold,PWT)的变化。采用强迫游泳实验和糖水偏好实验检测大鼠抑郁样行为,采用RT-PCR检测不同时间点大鼠海马中BDNF m RNA的水平,采用ELISA和免疫组织化学法检测BDNF的表达变化。结果:足底注射CFA后1天50%PWT下降,持续至14天仍低于基础值。在强迫游泳实验中,注射CFA7天后的大鼠不动时间百分比增加,一直持续到CFA注射后14天。糖水偏好实验中注射CFA后7天组、14天组大鼠表现出对糖水偏好的降低,提示注射CFA后7天大鼠出现抑郁样行为并持续到第14天。在足底注射CFA第7天后BDNF m RNA和BDNF的水平达到高峰,第14天表达下调并基本恢复正常水平。结论:结果提示,足底注射CFA能诱导大鼠产生炎性痛,CFA注射7天后出现抑郁样行为,此时海马内BDNF m RNA和BDNF蛋白水平均上调,可能与足底注射CFA后出现的抑郁样行为的发生密切相关。     

刺五加胶囊改善抑郁大鼠学习记忆能力及对海马BDNF 表达的影响

目的:探讨刺五加胶囊对抑郁大鼠学习记忆能力及对海马BDNF表达的影响。方法:SD大鼠随机分为正常组、模型组和刺五加胶囊低、中、高剂量组,21d慢性轻度不可预见性应激刺激法(CUMS)制备大鼠抑郁模型,对照组给予生理盐水1ml灌胃,刺五加胶囊低、中、高剂量组分别给予刺五加胶囊(200mg/kg,400mg/kg,800mg/kg)灌胃,取大鼠海马组织。分别采用Morris水迷宫法和免疫组织化学法观察大鼠大鼠学习记忆能力及对海马脑源性神经生长因子(BDNF)表达。结果:刺五加胶囊低剂量组能升高海马组织中BDNF的表达(P<0.05,P<0.01),降低大鼠逃避潜伏期(EL)时间,提高大鼠空间探索时间(SET)(P<0.05,P<0.01)。结论:刺五加胶囊能升高抑郁大鼠海马组织BDNF的表达,提升抑郁大鼠学习记忆能力。     

二甲双胍对慢性应激大鼠抑郁行为的影响

目的:观察二甲双胍对慢性不可预测性温和应激大鼠抑郁行为的影响。方法:40只雄性SD大鼠随机分为4组(n=10):对照组(CON组)、二甲双胍组(MET组)、模型组(CUMS组)、模型+二甲双胍组(CUMS+MET组),采用慢性不可预测性温和应激(CUMS)方法,用3周时间建立大鼠抑郁模型。造模完成后,两个二甲双胍组腹腔注射二甲双胍(100mg/kg),对照组和模型组注射等量的生理盐水,每天1次,连续2周。之后检测大鼠体重增长变化、糖水嗜好、强迫游泳和悬尾不动实验、旷场实验等大鼠行为学的改变,采用尼氏染色观察大鼠海马形态结构变化。结果:与对照组比较,CUMS组大鼠体重增长明显减慢(P<0.05),糖水偏爱率明显降低(P<0.05),强迫游泳和悬尾不动实验中不动时间明显延长(P<0.05),旷场实验中自发活动明显减少(P<0.05),大鼠海马的形态结构有所变化,证实CUMS抑郁模型建立成功。与CUMS组比较,二甲双胍处理后对大鼠的体重无明显影响,但能明显改善CUMS抑郁模型大鼠的糖水摄入、不动时间和自发活动(P<0.05),并能修复CUMS大鼠海马的异常形态结构变化。结论:二甲双胍对CUMS诱导的大鼠抑郁行为具有明显的改善作用,为临床糖尿病并发抑郁症的患者提供新的治疗手段。     

电针早期干预对创伤后应激模型大鼠的行为及前额叶皮质BDNF、IL-1β和IL-6水平的影响

目的:观察电针(Electroacupuncture,EA)早期干预对创伤后应激(Posttraumatic stress disorder,PTSD)模型大鼠的焦虑样行为及前额叶皮质(Prefrorntal cortex,PFC)中脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)、白介素1β(Interleukin-1beta,IL-1β)和白介素6(Interleukin-6,IL-6)水平的影响。方法:将32只雄性SD大鼠经环境适应后,随机分为Sham组、Sham+EA组、ESPS组和ESPS+EA组,每组8只。对ESPS组和ESPS+EA组大鼠进行增强型单次延长应激(Enhanced single prolonged stress,ESPS)造模处理,其他两组不接受ESPS,但是置于同一实验室环境。造模结束后24 h,各组大鼠进行EA干预:Sham+EA组和ESPS+EA组的大鼠每天接受EA刺激(百会穴,1 m A,2/15 Hz)30 min,连续1周;另外两组给予假刺激(无电流)每天30 min,连续1周。静置一周后,采用旷场和高架十字实验观察各组大鼠的行为,之后处死大鼠,分别用蛋白质印迹法和酶联免疫法(Enzyme-linked immunosorbent assay,ELISA)检测各组大鼠PFC中BDNF的表达水平以及IL-1β和IL-6的水平。结果:(1)ESPS处理导致大鼠焦虑样行为,在旷场中心区运动距离和探索时间百分比减少,在高架十字开臂运动距离及停留时间百分比减少。ESPS组大鼠PFC中BDNF表达下降,IL-1β和IL-6的水平升高;(2)EA早期干预可以改善大鼠的焦虑样行为,提高ESPS模型大鼠PFC中BDNF的表达,降低IL-6的水平,对IL-1β的影响无统计学差异。结论:EA早期干预改善了ESPS诱导的大鼠焦虑样的行为,这可能与其增加了PFC中BDNF表达,降低了炎性因子IL-6的表达有关。     

Gastrodin Ameliorates Depressive-Like Behaviors and Up-Regulates the Expression of BDNF in the Hippocampus and Hippocampal-Derived Astrocyte of Rats

Gastrodin (GAS), a main constituent of a Chinese herbal medicine Tian ma, has been shown to be effective in treating various mood disorders. The purpose of the present study was to assess the effects of GAS on alleviating depressive-like behaviors in a rat model of chronic unpredictable stress (CUS) and regulating the expression of BDNF in the hippocampus and hippocampal-derived astrocyte from Sprague–Dawley (SD) rats. Following CUS, rats were intraperitoneally administered gastrodin (50, 100, or 200 mg/kg daily) or vehicle for 2 weeks. Rats were then experienced sucrose preference test and forced swim test. The expressions of GFAP and BDNF in the hippocampus were evaluated. In addition, hippocampal astrocytes were isolated from neonatal SD rats and exposed to different concentrations of GAS (sham, 5, 10, 20, 50 and 100 μg/mL) for 48 and 72 h before the cell viability and the levels of pERK1/2 and BDNF were analyzed. Furthermore, the cell viability was also tested after exposure to serum-free condition that contain different concentrations of GAS for 48 and 72 h. GAS administration (100 and 200 mg/kg daily) reversed depressive-like behaviors in rats exposed to CUS paradigm and restored the expression of GFAP and BDNF in the hippocampus. Moreover, in vitro experiments revealed that GAS did not increase the cell viability of astrocytes but protected it from 72 h’s serum-free damage at the dosage 20 μg/mL. Increased levels of ERK1/2 phosphorylation and BDNF protein were also observed after GAS (20 μg/mL) treatment for 72 h. These results indicate that gastrodin possesses antidepressant effect. The changes of the astrocyte activation and the level of BDNF may play a critical role in the pharmacological action of GAS.     

乌灵菌粉水提物对MCAO小鼠海马结构及BDNF,GABA水平的影响

目的:探讨乌灵菌粉(xylaria nigripes,XN)水提物对脑缺血再灌注模型小鼠海马形态和高分子量神经丝蛋白(neurofilament high molecular weight,NF-H)表达以及脑源性神经营养因子(brain derived neurotrophic factor,BDNF)和γ氨基丁酸(γ-aminobutyric acid,GABA)的影响。方法:将32只昆明小鼠随机分为对照组(sham)、模型组(MCAO)和乌灵菌粉水提物低、高剂量组,即XN(L)和XN(H)。sham组进行假手术(皮肤切开,分离颈动脉),模型组(MCAO)及乌灵菌粉组进行大脑中动脉闭塞(middle cerebral artery occlusion,MCAO),sham组和MCAO组术后即刻腹腔注射生理盐水,乌灵菌粉组则注射不同剂量的乌灵菌粉水提物(0.3 g/kg和0.6 g/kg),术后24 h,通过尼氏染色、免疫组化染色和酶联免疫吸附实验(enzyme-linked immunosorbent assay,Elisa)分别观察海马结构和NF-H的表达情况以及BDNF和GABA水平。结果:(1)模型组小鼠海马出现大量的空洞样改变,细胞排列不整齐,XN(H)组空洞样改变减少;(2)模型组NF-H染色的积分光密度显著低于对照组和XN(H)组,差异具有统计学意义(P0.05);(3)Elisa检测显示,模型组海马BDNF和GABA水平显著低于对照组和XN(H)组,差异具有统计学意义(P0.01),而且模型组与XN(L)组的GABA水平之间也存在显著性差异(P0.05)。结论:乌灵菌粉水提物对MCAO模型小鼠海马结构具有保护作用,这一作用可能与其调节GABA和BDNF水平有关。     

Rosmarinic Acid Ameliorates Depressive-Like Behaviors in a Rat Model of CUS and Up-Regulates BDNF Levels in the Hippocampus and Hippocampal-Derived Astrocytes

Rosmarinic acid (RA), a primary constituent of a Chinese herbal medicine, has been shown to have some therapeutic effects in an animal model of depression, but its underlying mechanisms are poorly understood. Sprague–Dawley rats were exposed to chronic unpredictable stress (CUS) for 21 days, and received RA for 14 days from the last week of CUS, then the behavioral changes, hippocampal pERK1/2 and BDNF levels were observed. Rats were further treated with U0126 (an ERK1/2 phosphorylation inhibitor) 30 min before RA treatment to assess the effects of RA and ERK1/2 signaling in depressive-like behavior and hippocampal BDNF levels. In addition, brains of newly born Sprague–Dawley rats were used to harvest and expand hippocampal astrocytes. Cells were exposed to different concentrations of RA (sham, 1, 5, 10, 20, and 40 μg/mL) or U0126 (2 μM as a final concentration) + RA (sham, 1, 5, 10, 20, and 40 μg/mL) for 48 h, and the pERK1/2 and BDNF levels were assessed by western and ELISA assays. RA administration (10 mg/kg daily) reversed depressive-like behaviors in rats exposed to a chronic unpredictable stress paradigm and restored pERK1/2 protein expression and hippocampal brain-derived neurotrophic factor (BDNF). Moreover, in vitro experiments revealed that 20 μg/mL RA increased pERK1/2 and BDNF levels in cultured astrocytes. Interestingly, the effects of RA were inhibited by U0126. RA might be a useful treatment for depression and the changes in ERK1/2 signaling and BDNF levels may play a critical role in the pharmacological action of RA.     

后处理对心肌缺血再灌注致脑损伤中炎症因子及GFAP的影响

目的:探讨缺血后处理对心肌缺血再灌注致脑损伤中炎症因子及胶质纤维酸性蛋白的影响。方法:24只雄性SD大鼠随机分为3组(n=8),假手术组(Sham)、心肌缺血/再灌注组(IR)、后处理组(IPost)。结扎大鼠冠状动脉左前降支30 min,复流120 min建立大鼠心肌缺血/再灌注模型。后处理组于再灌注前进行缺血后处理,再灌注10 s,缺血10 s,共3次。断头处死大鼠取脑组织,光镜下观察病理学结果,Western blot检测炎性因子IL-6、IL-8、IL-10,免疫组化法检测GFAP。结果:与Sham组相比较,IR组脑组织炎症因子IL-6,IL-8表达增加,IL-10下降(P0.01),而后处理可以降低脑组织中IL-6,IL-8的表达,增加IL-10的表达(P0.01);与Sham组相比较,IR组脑组织GFAP表达增多(P0.05),而后处理可以显著增加脑组织中GFAP的表达(P0.01)。结论:心肌缺血后处理可以减少脑组织中炎症因子的表达,增加GFAP的表达,从而起到脑保护作用。     

Antidepressant-like effect of the water extract of the fixed combination of Gardenia jasminoides,Citrus aurantium and Magnolia officinalis in a rat model of chronic unpredictable mild stress

BackgroundWater extract of the fixed combination of Gardenia jasminoides Ellis fruit, Citrus aurantium L. fruit and Magnolia officinalis Rehd. et Wils. bark, traditional name – Zhi-Zi-Hou-Po (ZZHPD) is used for treatment of depressive-like symptoms in traditional Chinese medicine for centuries.Hypothesis/PurposeThe present study aimed to explore antidepressant-like effects and potential mechanisms of ZZHPD in a rat model of chronic unpredictable mild stress (CUMS).Study designAntidepressant-like effects of ZZHPD were investigated through behavioral tests, and potential mechanism was assessed by neuroendocrine system, neurotrophin and hippocampal neurogenesis.MethodsAntidepressant-like effects of ZZHPD (3.66, 7.32 and 14.64 g/kg/day) were estimated through coat state test, sucrose preference test, forced swimming test and open-field test. Effects of ZZHPD on hypothalamic-pituitary-adrenal (HPA) axis were evaluated by hormones measurement and dexamethasone suppression test. In addition, the expression of brain-derived neurotrophic factor (BDNF) in hippocampus was measured, as well as hippocampal neurogenesis was investigated by doublecortin (DCX) and 5-bromo-2-deoxyuridine/neuronal nuclei (BrdU/NeuN).ResultsThe results demonstrated that ZZHPD significantly reversed the depressive-like behaviors, normalized the levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT), restored the negative feedback loop of HPA axis and improved the levels of BDNF, DCX and BrdU/NeuN compared with those in CUMS-induced rats.ConclusionThe above results revealed that ZZHPD exerted antidepressant-like effects possibly by normalizing HPA axis function, increasing expression of BDNF in hippocampus and promoting hippocampal neurogenesis.     

亚麻木酚素对2型糖尿病小鼠学习记忆的影响及其机制初探

目的:研究亚麻木酚素(Flax ligands,FL)对2型糖尿病模型小鼠空间学习记忆的影响及其初步机制。方法:雄性C57小鼠随机分为对照组(Con)、糖尿病模型组(DM)及亚麻木酚素治疗组(DM+FL),DM与DM+FL组给予高脂饮食加小剂量链脲佐菌素(Streptozotocin,STZ)诱导2型糖尿病模型,之后DM+FL组灌胃给予FL 10 mg/kg,每日一次,连续14天,Con与DM组给予等量生理盐水。通过新物体识别试验、Morris水迷宫试验检测小鼠的学习记忆能力,利用Western blot技术测定小鼠海马脑源性神经营养因子(BDNF)及谷酰胺AMPA受体845位磷酸化(pGluA1-Ser845)蛋白表达水平。结果:与Con组比较,DM组小鼠新物体识别指数显著下降(P<0.01),在Morris水迷宫中逃避潜伏期延长(P<0.05),在目的象限内徘徊时间减少(P<0.01);小鼠海马区BDNF和pGluA1-Ser845的蛋白表达水平均显著低于对照组(P<0.01)。与DM组相比,DM+FL组小鼠新物体识别指数显著提高(P<0.01),在Morris水迷宫中逃避潜伏期明显缩短(P<0.05),目的象限徘徊时间显著增多(P<0.05);小鼠海马区BDNF和pGluA1-Ser845的蛋白表达水平均显著升高(P<0.01)。结论:亚麻木酚素对2型糖尿病小鼠学习记忆有明确改善作用,增加海马BDNF和pGlu-A1-Ser845的表达可能是其潜在作用机制。     

Chronic Unpredictable Stress Before Pregnancy Reduce the Expression of Brain-Derived Neurotrophic Factor and N-Methyl-D-Aspartate Receptor in Hippocampus of Offspring Rats Associated with Impairment of Memory

To investigate the effect of stress before pregnancy on memory function and serum corticosterone (COR) levels, as well as the expression of brain-derived neurotrophic factor (BDNF), N-methyl-D-aspartate (NMDA) 2A (NR2A) and 2B (NR2B) receptors in the hippocampus of the offspring rats when they were 2 months postnatally. Adult female Sprague-Dawley (SD) rats were divided randomly into two groups: control group (n = 8) and chronic unpredictable stress (CUS) group (n = 12). All rats were tested in the open field test and sucrose intake test before and after CUS. The memory function of their offspring were tested in the Morris water maze. Serum COR levels were determined by using a standard radioimmunoassay kit. The expression of BDNF, NR2A and NR2B in the hippocampus of the offspring rats were studied by immunoreactivity quantitative analysis and real-time RT-PCR. (1) Following CUS, reduced open field test activity and decreased sucrose consumption were observed relative to controls. (2) The Morris water maze task demonstrated increased escape latency in the offspring rats of CUS group relative to controls (P < 0.01). No-platform probe testing showed reduced crossings for offspring of CUS relative to controls (P < 0.05). (3) CUS induced a significant increase in serum COR levels of the offspring rats (P < 0.01), but no difference was observed in the body or brain weight between the offspring of the two groups. (4) Immunoreactivity quantitative analysis shows that BDNF and NR2B in the offspring of CUS group was decreased in the CA3 and DG regions of the hippocampus compared to the control group offspring, but NR2A levels were not altered between the offspring of the two groups. (5) Real-time RT-PCR demonstrated that BDNF and NR2B mRNAs were significantly decreased in the offspring of the CUS group compared with the control group (P < 0.01). No significant difference in the levels of NR2A mRNA was detected between offspring of CUS and offspring of control groups. In our study, pregestational stress can increase serum corticosterone levels and reduce the expression of BDNF and NR2B in the hippocampus of offspring. These alterations are associated with impairment of memory in the adult offspring. These data suggest that, stress before pregnancy might have a profound influence on brain development of offspring, that may persist into and be manifested in adulthood.     

不同浓度沙利度胺对大鼠慢性坐骨神经缩窄模型的镇痛效果及机制

目的:比较不同剂量沙利度胺对大鼠慢性坐骨神经缩窄(chronic sciatic nerve constriction,CCI)的镇痛效果及可能机制。方法:将50只大鼠随机分为S组、C组、L组、M组及H组,S组作为假手术组,其余四组建立CCI模型,术后分别用20 mg/kg、50mg/kg、100 mg/kg沙利度胺处理L组、M组、H组。于术后第1、2、3、4周测量和比较各组大鼠机械性痛阈与热痛阈,采用蛋白质印迹法(Western blot)及实时荧光定量PCR(Q-PCR)检测各组大鼠肿瘤坏死因子受体(TNFR)的mRNA和蛋白表达,并分析沙利度胺浓度与TNFR mRNA相对表达的相关性。结果:S组术前术后的机械性痛阈与热痛阈均无明显改变(P0.05),其余四组术后痛阈均较术前明显下降(P0.05);C组术后第4周时机械性痛阈明显升高(P0.05),而术后其他时间点的机械性痛阈与热痛阈无明显差异(P0.05);L组、M组、H组术后机械性痛阈、热痛阈随时间的延长呈上升趋势,差异有统计学意义(P0.05)。术后,C组机械性痛阈与热痛阈对比S组明显降低(P=0.000),亦显著低于L组(P=0.000);而不同剂量组机械性痛阈、热痛阈相比,H组高于M组(P=0.000),M组高于L组(P=0.000)。相对于C组,L组、M组、H组术后第4周TNFR1 mRNA及蛋白相对含量显著下降(P0.05),其中H组下降最为明显,M组次之。Pearson相关性分析结果显示:沙利度胺浓度的增加与TNFR1表达水平的升高呈明显负相关关系(r=-0.497,P=0.036)。结论:沙利度胺可能通过影响TNFR表达水平对大鼠慢性坐骨神经缩窄发挥镇痛效应,其镇痛效应随剂量增加而加强,有望作为神经病理性疼痛的辅助镇痛药物之一。     

Brain-derived neurotrophic factor superinduction parallels anti-epileptic--neuroprotective treatment in the pilocarpine epilepsy model

Antiepileptic drugs provide neuroprotection in several animal models of brain damage, including those induced by status epilepticus (SE). The mechanisms involved in this action are unknown, but neurotrophic factors such as brain-derived neurotrophic factor (BDNF) may play a role. In this study we investigated the changes in BDNF levels in rats in which SE had been induced by pilocarpine injection (400 mg/kg i.p.) and continued for several hours (unprotected group). In other animals (protected groups), SE was suppressed after 30 min by intraperitoneal injection of either diazepam (10 mg/kg) + pentobarbital (30 mg/kg) or paraldehyde (0.3 mg/kg). In diazepam + pentobarbital-treated rats the hippocampal damage caused by SE was significantly lower (p < 0.05) than in unprotected animals. In addition, 2 and 24 h after pilocarpine injection, the levels of BDNF mRNA were moderately increased in the unprotected group, but 'superinduced' in protected animals, especially in the neocortex and hippocampus. A time-dependent increase in BDNF immunoreactivity was also found by western blot analysis in rats treated with diazepam + pentobarbital. In contrast, a decrease of BDNF immunoreactivity occurred in the unprotected group. In conclusion, these results show that neuroprotection induced by anti-epileptic drugs in pilocarpine-treated rats is accompanied by strong potentiation of BDNF synthesis in brain regions involved in SE.