血管性痴呆大鼠海马突触素、发动蛋白Ⅰ的mRNA及蛋白表达变化

目的探讨血管性痴呆(VaD)大鼠海马突触素、发动蛋白Ⅰ的mRNA及蛋白表达变化。方法利用改良四血管法制备血管性痴呆大鼠模型。通过Morris水迷宫观察大鼠空间探索及学习记忆情况,采用Real-time及Western-blot法分别检测大鼠海马突触素、发动蛋白Ⅰ的mRNA与蛋白水平,并与假手术组进行比较。结果 VaD组大鼠各时间点平均逃避潜伏期及第1次穿越平台所用时间均显著长于假手术组(均P0.01),平台穿越次数明显减少(P0.05)。VaD组海马突触素及发动蛋白Ⅰ蛋白表达及mRNA表达显著低于假手术组(P0.05~0.01)。结论脑缺血引起大鼠海马组织突触素、发动蛋白Ⅰ表达降低,可能与VaD发病中学习记忆能力减退有关。     

黄芪多糖对颅脑损伤大鼠学习记忆能力及海马BDNF表达的影响

目的探讨黄芪多糖(APS)对颅脑损伤大鼠学习记忆能力及海马组织脑源性神经生长因子(BDNF)表达的影响。方法将30只成年雄性SD大鼠按随机数字表随机分为3组:假手术组、TBI组、APS组,每组10只。TBI组和APS组建立颅脑损伤大鼠模型,假手术组不建模型。假手术组、TBI组分别给予生理盐水灌胃,APS组给予APS悬液(100 mg/kg)灌胃;每天1次,持续8周。采用Morris水迷宫实验测试大鼠学习记忆能力。水迷宫实验结束后,RT-PCR与Western blot测定海马组织BDNF mRNA和蛋白表达水平。结果与假手术组比较,TBI组大鼠逃避潜伏期明显延长(P0.05),平台象限路径百分比和平台象限时间明显缩短(P0.05),海马组织BDNF mRNA和蛋白表达水平明显降低(P0.05);与TBI组比较,APS组大鼠逃避潜伏期明显缩短(P0.05)、平台象限路径百分比和平台象限时间明显延长(P0.05),海马组织BDNF mRNA和蛋白表达水平明显升高(P0.05)。结论APS能够减轻颅脑损伤所致的大鼠学习记忆能力减退,可能与提高BDNF表达水平有关。     

骨髓间充质干细胞移植对血管性痴呆大鼠认知功能及一氧化氮合酶的表达的影响

目的探讨骨髓间充质干细胞(BMSCs)侧脑室移植对血管性痴呆(Va D)大鼠认知功能及一氧化氮合酶(NOS)的表达的影响。方法将SD大鼠分为BMSCs组、培养基组及假手术组。BMSCs组大鼠侧脑室注射BMSCs,培养基组大鼠侧脑室注射DMEM基础培养液。移植后30 d比较各组大鼠学习记忆能力,血浆和海马组织TNOS和i NOS的酶活性及NO水平、血液NOS mRNA、海马组织NOS mRNA、NOS蛋白水平。结果与假手术组比较,BMSCs组及培养基组逃避潜伏期及第1次穿越平台时间显著延长(均P0.05),穿越平台次数明显减少(P0.05)。与培养基组比较,BMSCs组大鼠逃避潜伏期及第1次穿越平台时间显著缩短(均P0.05),穿越平台次数显著增加(均P0.05)。培养基组和BMSCs组大鼠血浆、海马组织t NOS、i NOS酶活性及NO水平均显著高于假手术组(均P0.05)。BMSCs组大鼠血浆、海马组织t NOS、i NOS酶活性及NO水平均明显低于培养基组(均P0.05)。与假手术组比较,培养基组和BMSCs组血浆、海马组织NOS mRNA及海马组织NOS蛋白表达水平均显著增高(均P0.01)。BMSCs组血浆、海马组织NOS mRNA及海马组织蛋白NOS表达水平较培养基组显著降低(均P0.05)。结论 BMSCs侧脑室移植能够降低Va D大鼠的NO水平及t NOS、i NOS酶活性,从而发挥一定神经保护作用,改善大鼠的认知功能。     

白藜芦醇对AD大鼠学习记忆能力和海马P-tau表达的影响

目的探讨白藜芦醇(Resveratrol,Res)对阿尔茨海默病(Alzheimer’s disease,AD)模型大鼠学习记忆能力的影响及作用机制。方法 50只雄性SD大鼠随机分为假手术组、模型组和白藜芦醇高、中、低剂量组。采用Aβ双侧海马注射建立AD大鼠模型。水迷宫试验观察大鼠学习记忆能力的变化,HE染色观察大鼠海马组织形态结构变化,免疫组化SP法检测大鼠海马组织P-tau的表达。结果白藜芦醇可改善AD大鼠的学习记忆能力(P<0.01),减少海马神经元丢失,显著性降低海马P-tau蛋白的表达(P<0.01)。结论白藜芦醇能改善AD模型大鼠的学习记忆功能,其作用机制可能与有效降低P-tau蛋白有关。     

普罗布考对血管性痴呆大鼠认知功能及海马区JNK、p-JNK表达的影响

目的观察普罗布考对血管性痴呆(VD)大鼠的认知功能及海马区JNK、p-JNK表达的影响。方法将30只雄性SD大鼠随机分为假手术组、模型组、普罗布考组,采用永久性结扎双侧颈总动脉的方法制作VD大鼠模型,灌胃给予普罗布考8w后通过Morris水迷宫观察大鼠的学习记忆能力,采用流式细胞术评估大鼠海马神经元凋亡率,免疫组织化学法和蛋白印迹(Western blot)法检测大鼠海马c-Jun氨基末端激酶(JNK)、磷酸化的c-Jun氨基末端激酶(p-JNK)的表达。结果与假手术组相比,模型组大鼠学习记忆能力明显减弱,大鼠海马细胞凋亡率显著增高,海马区p-JNK蛋白的表达水平增高。应用普罗布考后大鼠学习记忆能力明显提高,海马细胞凋亡率显著降低,海马区p-JNK蛋白的表达水平降低。结论普罗布考可以改善VD大鼠的学习记忆能力,其机制可能与其抑制JNK信号通路的异常激活有关。     

钙调神经磷酸酶对阿尔茨海默病大鼠模型海马区PSD-95及Homer、Shank基因各亚型表达的影响

目的探讨钙调神经磷酸酶(Calcineurin,Ca N)对阿尔茨海默病(Alzheimer’s disease,AD)大鼠模型海马区PSD-95及Homer、Shank基因各亚型表达的影响及其作用机制。方法采用Aβ1-42海马注射建立AD大鼠模型,并用他克莫司(FK506)干预,以Morris水迷宫检测大鼠的空间学习记忆能力,并用实时定量PCR(RealTime PCR)检测大鼠海马区PSD-95及Homer、Shank各亚型的mRNA表达情况。结果与对照组相比,模型组大鼠学习记忆能力明显减退(P<0.01),PSD-95、Homer1b、Shank1、Shank3的mRNA表达均下调,而Homer1a的mRNA表达上调(P<0.05)。FK506干预后,与模型组比较,学习记忆能力显著改善(P<0.01),同时PSD-95、Homer1b、Shank1、Shank3的mRNA表达均上调(P<0.05),而Homer1a的mRNA表达下调(P<0.01)。Shank2的mRNA表达在三组中均未见显著性差异(P>0.05)。结论抑制Ca N激活可明显增高海马区突触相关蛋白在基因的表达水平,从而影响突触的功能和可塑性,这可能是其改善AD症状的作用机制之一。     

GCs对VD大鼠行为学及海马脑区tau蛋白P-tau蛋白、Aβ淀粉样蛋白表达影响的实验研究

目的研究肉苁蓉总苷(glycosides of cistanche,GCs)对血管性痴呆(vascular dementia,VD)模型大鼠行为学及海马脑区tau蛋白、p-tau蛋白、Aβ淀粉样蛋白表达的影响,探讨GCs对VD的防治作用。方法双侧颈总动脉结扎(2-VO法)建立VD大鼠模型,随机分为假手术组、VD模型组、GCs低、中、高剂量治疗组和药物对照共6组,Morris水迷宫实验评价各组大鼠的空间学习记忆能力;免疫组化方法检测海马脑区tau蛋白、p-tau蛋白、Aβ淀粉样蛋白表达量的改变。结果 (1)Mories水迷宫研究发现术后1 d、2 d、3 d、4 d、5 d VD组大鼠逃避潜伏期明显延长,与假手术组相比差异明显,有统计学意义(P<0.01,P<0.05);GCs治疗后,VD大鼠定位航行试验的逃避潜伏期显著缩短,有统计学意义(P<0.01);但GCs中剂量组与药物对照组相比差异无统计学意义;(2)模型组大鼠海马脑区tau蛋白、P-tau蛋白、Aβ淀粉样蛋白表达量均显著上升;GCs治疗后,表达量显著下降,与模型组相比(P<0.05),差异有统计学意义。结论 (1)本研究发现tau蛋白、p-tau蛋白、Aβ淀粉样蛋白表达量显著升高,推测VD发病过程与其他类型痴呆如AD存在共同的病理特征;(2)GCs通过减少VD大鼠海马脑区tau蛋白、p-tau蛋白、Aβ淀粉样蛋白表达,有效改善VD模型大鼠的认知功能。     

血管性痴呆大鼠海马神经型胆碱能受体的变化

目的 探讨血管性痴呆(VD)大鼠海马神经型胆碱能受体(nAChR)的变化.方法 改良四血管法建立VD大鼠模型;术后1个月,采用Morris水迷宫试验检测VD大鼠的学习和记忆功能;应用改良Ellman法测定大鼠血浆及海马乙酰胆碱酯酶(AChE)活性;Western Blot法及RT-PCR法分别检测大鼠海马nAChR亚单位α3、α4、α7蛋白及mRNA的表达水平,并与假手术组比较.结果 与假手术组相比,VD组水迷宫试验逃避潜伏期明显延长,第1次穿越平台时间延长,穿越平台次数减少(均P<0.01);血浆AChE活性降低(P<0.01),海马AChE活性升高(P<0.05);海马nAChR α3、α4、α7蛋白及nAChR α3、α7 mRNA表达水平明显下降(P<0.05～0.01),nAChR α4 mRNA表达水平明显升高(P<0.01).结论 海马神经元nAChR表达的降低可能是VD大鼠认知功能受损害的基础.     

二甲双胍对阿尔茨海默病大鼠的疗效及机制研究

目的观察二甲双胍对阿尔茨海默病(Alzheimer’s disease,AD)大鼠学习记忆能力的影响,并进一步探讨其可能机制。方法将50只雄性SD大鼠随机分为正常组、假手术组、模型组和治疗组。模型组和治疗组大鼠双侧海马各注射5μl Aβ25-35(2 g/L)建立AD模型,假手术组注射等量生理盐水。次日,对治疗组大鼠予以二甲双胍灌胃治疗,100 mg/(kg·d),连续给药2 w。干预结束后,检测各组大鼠学习记忆能力、海马区细胞基本情况及PI3K、AKT、P-AKT、GSK3β、P-GSK3β、tau[p S202]、tau5的相对表达量。结果二甲双胍能显著改善AD模型大鼠的认知能力(P 0.05);各组大鼠海马区细胞基本形态结构无明显差异;与正常组相比,假手术组上述蛋白相对表达量无明显改变,但模型组大鼠海马组织中PI3K、P-AKT/AKT、P-GSK3β/GSK3β的表达情况明显下调(P 0.05),干预后有所改善(P 0.05);模型组中tau[p S202]/tau5明显高于正常组和假手术组,干预后tau蛋白磷酸化程度降低(P 0.05)。结论二甲双胍能够有效改善AD模型大鼠学习记忆能力,其机制可能与"PI3K-AKTGSK3β-tau磷酸化"信号通路密切相关。     

银杏叶提取物对阿尔茨海默病模型大鼠神经功能的影响

目的探讨银杏叶提取物(GBE)对阿尔茨海默病(AD)模型大鼠学习和记忆行为、海马组织中氧化自由基及内质网应激的影响。方法腹腔注射D-半乳糖诱导构建大鼠AD模型。将15个月龄的雄性Wistar大鼠,随机分为对照组、AD组、AD+GBE组、AD+GBE+内质网应激诱导剂衣霉素(AD+GBE+Tm组),每组12只。采用Morris水迷宫测定大鼠学习和记忆行为;试剂盒检测海马组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;Western blot方法测定激活转录因子6(ATF-6)和CCAAT/增强子结合蛋白(CHOP)的表达。结果与对照组比较,AD组、AD+GBE组和AD+GBE+Tm组大鼠逃避潜伏期明显延长,目标象限内游泳距离占总距离的百分比明显降低,海马组织氧化自由基MDA、抗氧化酶SOD和内质网相关因子(ATF-6、CHOP)蛋白表达上调(P0.05);与AD组比较,AD+GBE组大鼠逃避潜伏期明显缩短,目标象限内游泳距离占总距离的百分比明显增加(P0.05),海马组织中氧化自由基MDA表达降低,抗氧化酶SOD活性增加;同时内质网应激相关因子ATF-6和CHOP蛋白表达减少(P0.05)。与AD+GBE组比较,AD+GBE+Tm组氧化自由基MDA表达增加,抗氧化酶SOD活性降低;内质网应激相关因子ATF-6和CHOP蛋白表达增加(P0.05)。结论 GBE能抑制内质网应激反应,抑制氧化自由基产生,改善AD模型大鼠学习和记忆功能,缓解AD病情。     

Genetic findings in obsessive-compulsive disorder in childhood and adolescence and in adulthood

Obsessive-compulsive disorders (OCD) are on the rise, and affected children, 1-2% of the general population, often are seriously impaired in their development. OCD is characterized by recurrent, intrusive and disturbing thoughts as well as by repetitive stereotypic behaviours. Depending on their age and developmental status, patients usually try unsuccessfully to suppress the obsessive thoughts and compulsive behaviours. The current state of genetic research on OCD and early-onset OCD is presented and discussed. OCD, especially early-onset OCD, has been shown to be familial. Convincing evidence indicates that both environmental and genetic factors substantially influence OCD. Various approaches, including linkage and association studies, yielded conflicting results as well as the notion that multiple genes of modest effect sizes, in interaction with environmental factors, cause vulnerability to the disorder. The phenotypic and genetic heterogeneity of OCD complicate the identification of specific genetic factors. Further studies have to be designed in consideration of subtypes, e.g. age at onset, symptom dimensions, or comorbid disorders.     

Changes in extra- and intracellular pH in the brain during and following ischemia in hyperglycemic and in moderately hypoglycemic rats

Incomplete forebrain ischemia of 15-min duration was induced in rats made hyperglycemic or moderately hypoglycemic prior to ischemia. Tissue CO2 tension, CO2 content, labile tissue metabolites, and extracellular pH (pHe) were measured, and intracellular pH (pHi) was derived by calculation on the assumption that cerebral intracellular fluids can be lumped into one space. In hypoglycemic animals, mean tissue lactate content increased from 2 to 10 mumol g-1. Tissue CO2 content was virtually unchanged and the CO2 tension increased from approximately 50 to approximately 145 mm Hg. In hyperglycemic animals, tissue lactate content rose to 20 mumol g-1, and the CO2 content decreased by 25%, demonstrating that some CO2 was lost to the blood supplied by the remaining perfusion. Accordingly, tissue CO2 tension did not rise above 200 mm Hg. pHe was reduced in proportion to the amount of lactate accumulated, the values obtained in hypo- and hyperglycemic animals showing relatively little scatter (6.76 +/- 0.03 and 6.25 +/- 0.04, respectively). In hypoglycemic animals the extracellular HCO-3 concentration was virtually unchanged, demonstrating that any influx of lactic acid from the cells must have been accompanied by H+ efflux and/or HCO-3 influx via independent routes. In hyperglycemic animals [HCO-3]e fell by greater than 10 mumol ml-1. In both groups [HCO-3]e was reduced during the first 5 min of recovery. Recovery of pHe was slower in hyper- than in hypoglycemic animals. During ischemia calculated pHi fell to 6.37 +/- 0.04 and 5.95 +/- 0.06 in hypo- and hyperglycemic animals, respectively. Differences in pHi were maintained for the first 15 min of recovery, but in both hypo- and hyperglycemic animals pHi had normalized after 30 min. It is concluded that preischemic hyperglycemia leads to a more pronounced intra- and extracellular acidosis than normo- and hypoglycemia, an acidosis that also resolves more slowly during recirculation.     

Dopamine-derived alkaloids in alcoholism and in Parkinson's and Huntington's diseases

Summary Tetrahydroisoquinoline (TIQ) alkaloids and 1-carboxy TIQ derivatives have been found in human fluids and/or tissues. The possible biosynthetic pathways of salsolinol (Sal), taken as an example of TIQs, are discussed, and the possibility that biosynthesis occurs through a stereospecific enzymatic reaction is considered. In this respect, it is reported that the R enantiomer of Sal predominates in urines of healthy volunteers, whereas the S enantiomer predominates in port wine and possibly in other beverages and foods, suggesting that Sal present in humans could have, at least partially, and endogenous enzymatic origin.TIQs and other dopamine-derived alkaloids are weak MAO inhibitors, the R enantiomer of Sal and salsolidine being more potent than the S form.The changes in monoamine oxidase activity and the nigrostriatal concentrations of dopamine and homovanillic acid in Parkinson's and Huntington's diseases and in alcoholism are reviewed. In these pathological situations, changes in the levels of dopamine-derived alkaloid levels may occur. The possibility that the modifications found might cause or contribute to changes in mental and/or neurophysiological states in these pathological situations is considered.