褪黑素对Alzheimer病模型大鼠认知功能和海马tau蛋白过度磷酸化的影响

目的 研究褪黑素(MT)对Alzheimer病(AD)模型大鼠认知功能和海马tau蛋白过度磷酸化的影响.方法 给大鼠海马内注射凝聚态β-淀粉样蛋白(Aβ)25-35制作AD模型;MT组大鼠从制模前7 d至制模后19 d每日腹腔注射MT,AD组大鼠制模后腹腔注射生理盐水;用Morris水迷宫试验检测大鼠的认知功能,银染法观察海马神经元形态,免疫组化法观察过度磷酸化tau蛋白的表达,并与正常对照组比较.结果 MT组大鼠Morris水迷宫试验结果明显好于AD组(均P＜0.001);海马CA1区磷酸化tau蛋白阳性细胞数(60.0±2.3)明显少于AD组(98.4±3.0)(P＜0.001),与正常对照组比较差异无统计学意义;海马CA1区神经元纤维形态较AD组规则.结论 MT可明显改善AD大鼠的认知功能,并且抑制海马tau蛋白的过度磷酸化.     

CART阻抑对阿尔茨海默病大鼠记忆能力的影响

目的探讨可卡因苯丙胺调节转录肽(CART)对阿尔茨海默病(AD)大鼠脑内β淀粉样蛋白(Aβ)生成和Tau蛋白磷酸化的影响。方法实验分为4组,依次为模型组(AD大鼠)、实验组(AD模型大鼠尾静脉注射CART)、假手术组(用等量的PBS代替Aβ_(1-40))、对照组(正常饲养)。脑侧室注射Aβ_(1-40)构建AD大鼠模型,Morris水迷宫检测各组大鼠逃避潜伏期和穿越平台次数,ELISA法检测脑组织中Aβ_(1-40)水平,RT-PCR检测脑组织中胰岛素降解酶(IDE)、中性内肽酶(NEP)、低密度脂蛋白受体相关蛋白(LRP-1)水平,Western blot检测脑组织中Tau蛋白磷酸化、IDE、LRP-1、NEP、糖原合成激酶3β(GSK-3β)、p-GSK-3β水平。结果实验组大鼠逃避潜伏期明显低于模型组,而穿越平台次数明显高于模型组。实验组大鼠Aβ_(1-40)水平、Tau 5水平、Tau磷酸化水平(Tau pSp~(199/202)、Tau~(pT231))、GSK-3β、p-GSK-3β明显低于模型组,而IDE、LRP-1、NEP明显高于模型组。结论CART能够通过调节IDE、LRP-1、NEP水平降低AD大鼠模型中Aβ_(1-40)水平,能够通过调节GSK-3β抑制Tau蛋白磷酸化,进而改善AD大鼠的记忆能力。     

尼莫地平对大鼠蛛网膜下腔出血后认知障碍及海马Tau蛋白的影响

目的探讨尼莫地平（ND）对大鼠蛛网膜下腔出血（SAH）后认知功能障碍及海马Tau蛋白的影响。方法将40只SD大鼠随机分成正常组、假手术组、SAH组、ND组,每组10只;采用枕大池单次注血法建立SAH模型;造模后30 d进行Morris水迷宫试验评估大鼠认知功能,TUNEL法检测海马细胞凋亡,免疫组化染色法检测海马Tau蛋白和磷酸化Tau蛋白表达。结果 1认知功能：SAH组和ND组潜伏期较正常组和假手术组明显延长（P〈0.05）,而ND组较SAH组明显缩短（P〈0.05）;SAH组和ND组平台象限游泳时间百分比较正常组和假手术组明显缩小（P〈0.05）,而ND组较SAH组明显增大（P〈0.05）。2海马病理改变：SAH组和ND组细胞凋亡较正常组和假手术组明显升高（P〈0.05）,而ND组较较SAH组明显减少（P〈0.05）;SAH组和ND组海马Tau蛋白及磷酸化Tau蛋白表达水平均明显高于正常组和假手术组（P〈0.05）,而ND组明显低于SAH组（P〈0.05）。结论 ND可改善大鼠SAH后认知功能障碍,可能与抑制细胞凋亡及降低海马Tau蛋白和磷酸化Tau蛋白的表达有关。     

胰高血糖素样肽1(GLP-1)改善阿尔茨海默病大鼠模型的认知功能及其机制研究

目的 探讨胰高血糖素样肽1(GLP-1)改善阿尔茨海默病大鼠认知功能的机制。方法 以正常成年雄性SD大鼠为研究对象,将其随机分为正常对照组、AD模型组、AD模型+GLP-1干预组和AD模型+PPARγ抑制剂+GLP-1干预组; 其中AD模型组以侧脑室注射STZ(3 mg/kg,10 μL)制造AD模型,AD模型+GLP-1干预组在AD造模基础上每日腹腔注射利拉鲁肽(200 μg/kg,10 μL),连续给药28 d,AD模型+PPARγ抑制剂+GLP-1干预组在AD造模基础上侧脑室注射PPARγ抑制剂GW9662(2.5 nmol/g,10 μL),随后腹腔注射利拉鲁肽(200 μg/kg,10 μL)并连续给药28 d; 观察4组大鼠在Morris水迷宫中的学习和记忆能力变化; ELISA方法观察各组大鼠海马Aβ42的水平; Western blot观察各组大鼠海马PPARγ蛋白表达水平。结果 与AD模型组比较,GLP-1干预后的AD大鼠在Morris水迷宫中学习和记忆能力明显改善,海马Aβ42的水平显著降低,海马PPARγ蛋白表达水平显著升高(P<0.05); 与AD模型+GLP-1干预组比较,AD模型+PPARγ抑制剂+GLP-1干预组大鼠海马PPARγ蛋白表达水平显著降低,在Morris水迷宫中学习和记忆能力明显下降,海马Aβ42的水平显著增高(P<0.05)。结论 GLP-1可能通过激活PPARγ抑制Aβ 蓄积,从而起到改善阿尔茨海默病的认知功能作用。     

高胆固醇对AD大鼠海马神经元缺失和Tau蛋白异常磷酸化的影响

目的 研究高胆固醇饮食对阿尔茨海默病(AD)大鼠海马神经元缺失和Tau(ser202)异常磷酸化的影响.方法 海马齿状同注射B淀粉样蛋白(A13)建立AD大鼠模型,根据不同饮食,将动物分为高胆同醇AD组、高胆同醇磷酸盐缓冲液(PBS)组、标准饮食AD组和标准饮食PBS组;采用尼氏染色方法检测海马神经元缺失率,应用免疫组织化学方法检测海马及皮层Tau(ser202)磷酸化水平.结果 高胆固醇饮食增加海马神经元缺失,高胆固醇饮食AD组海马神经元缺失率(30.9%±4.6%)明显大于标准饮食AD组(22.7%±1.9%)、高胆同醇饮食PBS组(7.O%±1.5%)和标准饮食PBS组(5.4%±1.1%),差异均有统计学意义(P＜0.05);高胆固醇AD组、标准饮食AD组、高胆固醇PBS组、标准饮食PBS组海马齿状回(Pser202)Tau阳性细胞数分别为65.5±6.2、48.8±4.8、22.5±3.1和12.7±1.7,比较差异均有统计学意义(P＜0,05).结论 高胆固醇饮食促进Aβ诱导神经元缺失和Tau蛋白异常磷酸化.     

经颅电刺激对阿尔兹海默病大鼠学习记忆能力和海马CA_1区磷酸化tau蛋白表达情况的影响

目的探讨经颅电刺激对阿尔兹海默病(Alzeheimer’s disease,AD)大鼠学习记忆能力和海马CA_1区磷酸化tau蛋白表达的影响。方法健康SD大鼠,随机分为:正常组、假手术组、模型组及经颅电刺激2 w、4 w、6 w组。采用大鼠侧脑室注射Aβ25-35凝聚态β-淀粉样肽,同时腹腔注射D-半乳糖的方法,建立AD动物模型。Morris水迷宫实验检测各组大鼠学习、记忆能力,HE染色,观察海马CA_1区形态学结构,免疫组化测定海马CA_1区磷酸化tau蛋白表达情况。结果 (1)Morris水迷宫实验大鼠测试学习和记忆能力,经颅电刺激2 w组与模型组比较差异无统计学意义(P0.05),经颅电刺激4 w组、6 w组与模型组比较,逃避潜伏期成绩均好于模型组,差异有统计学意义(P0.05);(2)随电刺激时间延长,经颅电刺激各组磷酸化tau蛋白量逐渐降低,与模型组比较差异有统计学意义(P0.05)。结论经颅电刺激能够改善阿尔兹海默病大鼠的学习记忆能力,机制可能与下调海马CA_1区磷酸化tau蛋白表达有关,对细胞的重塑有积极影响,远期效果有待进一步研究。     

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。     

冈田酸和β-淀粉样蛋白对大鼠CaMKⅡ与Tau蛋白磷酸化的影响

目的探讨冈田酸和β-淀粉样蛋白对大鼠CaMKⅡ与Tau蛋白磷酸化的影响。方法用立体定向方法将β-淀粉样蛋白(β-amyloid protein,Aβ)(1mg/ml、5μl/只)注入SD大鼠海马CA1区,1w后注射冈田酸(OA)0.4nmol/L、2μl/只,隔天注射共注射7次,以建立类AD动物模型。采用水迷宫、Western blotting和Real-time等方法对类AD模型进行行为学和分子生物学分析,检测类AD大鼠海马组织CaMKⅡ、磷酸化Tau蛋白的表达水平以及大鼠学习记忆力的变化。结果与对照组相比Aβ1-42海马注射组、OA注射组及共同注射Aβ1-42和OA组均能引起大鼠学习记忆力降低,CaMKⅡmRNA及蛋白表达增加(P0.01),Tau蛋白Ser404磷酸化增加(P0.05)。Aβ1-42与OA具有协同增加CaMKⅡmRNA及蛋白表达及Tau蛋白Ser404磷酸化的作用。结论 Aβ1-42和OA可降低大鼠学习记忆能力,增加CaMKⅡ表达和Tau蛋白Ser404磷酸化。     

Tau蛋白过度磷酸化对脑淀粉样蛋白生成的影响

目的研究tau蛋白过度磷酸化对脑淀粉样蛋白生成的影响。方法用蛋白磷酸酯酶抑制剂冈田酸（OA）在大鼠侧脑室内注射,每天1次连续8周。用Morris水迷宫和免疫组化方法观察OA组大鼠行为学改变、神经原纤维缠结及淀粉样蛋白的表达;并与对照组比较。结果与对照组相比,OA组大鼠Morris水迷宫平均潜伏期显著延长,学习获取能力较差,空间记忆能力衰退。OA组大鼠的海马CA1区、CA3区、CA4区、齿状回、大脑皮质出现tau蛋白磷酸化,神经原纤维缠结;大脑皮质及海马CA1区、CA3区、齿状回等部位出现β淀粉样蛋白沉积。结论Tau蛋白过度磷酸化可以增加脑部淀粉样蛋白的沉积。     

异丙酚对大鼠抑郁模型电休克治疗后认知功能和海马Glu浓度及Tau蛋白磷酸化程度的影响

目的探讨异丙酚对电休克治疗后抑郁大鼠认知功能及海马Glu浓度和Tau蛋白磷酸化的影响。方法选择雌性SD(Sprague Dawley)大鼠建立大鼠抑郁模型,利用旷场试验选择得分30~80分大鼠20只,随机分为4组(n=5):A组注射生理盐水,B组给予异丙酚,C组给予电休克治疗,D组给予电休克和异丙酚注射联合处理,E组正常小鼠,注射生理盐水。处理后3d进行Morris水迷宫试验,记录逃避潜伏期(s)、经过原平台位置次数(次)、原平台所在象限停留时间(s)。随后检测海马Glu浓度和Tau蛋白磷酸化程度。结果与A组相比较,C组逃避潜伏期(s)延长、经过原平台位置次数(次)、原平台所在象限停留时间(s)减少,海马Glu浓度和Tau蛋白磷酸化程度增高(P0.05);与C组相比,D组逃避潜伏期(s)缩短,经过原平台位置次数(次)、原平台所在象限停留时间(s)增加,海马Glu浓度和Tau蛋白磷酸化程度减低(P0.05)。结论ECT通过增高Glu浓度促进Tau蛋白磷酸化,影响抑郁大鼠认知功能,而异丙酚可以调节ECT引起的Glu浓度和Tau蛋白磷酸化程度,进而改善大鼠认知功能。     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.     

Summary of legislation of 1935 of interest to the department of Mental Hygiene

Psychiatric Quarterly -