不同鼠龄在慢性间断性缺氧相关认知损害中的作用及机制探讨

目的 阐明不同鼠龄在慢性间断性缺氧相关认知损害中的作用及可能机制。方法 采用改良的IH鼠箱建立慢性IH小鼠模型,利用Morris水迷宫检测青年和老年IH小鼠的认知功能; 通过氧疗的干预对比青年与老年小鼠认知损害及突触可塑性的改善程度,TUNEL法检测小鼠海马CA1区神经元凋亡情况,Western Blotting检测神经突触素、胰岛素信号通路蛋白[蛋白激酶B(Akt)、糖原合成激酶3β(GSK-3β)]的磷酸化表达水平变化。结果 老年小鼠IH组的逃避潜伏期最长,其海马CA1区见明显增多的TUNEL染色阳性细胞,脑细胞凋亡率最高(P<0.01),p-Akt、p-GSK3β表达水平显著降低(P<0.01),目标象限LD滞留时间与p-Akt、p-GSK3β均存在正相关。结论 老年使慢性间断性缺氧C57BL/6小鼠认知损害的易感性增加,可能的机制之一是调节胰岛素信号通路相关蛋白的表达异常。     

刺五加皂甙对大鼠血管性痴呆防治作用的研究

目的探讨刺五加皂甙对血管性痴呆(VD)模型大鼠学习记忆等认知功能的改善和对海马CA1区神经元的保护作用.方法SD大鼠随机分为正常组、(VD)模型组、刺五加皂甙组,采用4-血管阻断改良法制备VD大鼠模型,各组作避暗回避试验和跳台试验等行为学测试,Nissl染色.结果行为学测试表明刺五加皂甙能明显改善(VD)模型大鼠学习记忆等认知功能,形态学结果表明刺五加能减轻海马CA1区神经元丢失.结论刺五加皂甙能减轻海马脑缺血缺氧后神经元损害,从而改善(VD)模型大鼠学习记忆功能.     

慢性应激刺激成年小鼠对其老年期认知功能的影响

目的:观察慢性应激刺激成年小鼠对其老年期认知功能及海马区神经结构的影响。方法:将8周龄成年雄性小鼠予以慢性束缚性刺激6周(Stress,S组),束缚结束后成年S组小鼠即刻进行水迷宫行为学测试并断头以免疫组化学及硫堇染色方法观察海马区突触素及尼氏小体的变化,并利用医学图像分析系统计算突触素免疫组化反应阳性产物数量;而老年S组小鼠于慢性束缚6周后普通环境下继续饲养11周至老年期(25周龄)再进行上述行为学及病理学检测。对照组小鼠正常环境下饲养并分别于14周龄、25周龄进行上述行为学及病理学检测。结果:成年及老年S组小鼠学习记忆能力明显受损(P<0.05);海马区脑组织突触素免疫反应阳性产物和尼氏小体数量较同龄对照组小鼠明显减少(P<0.01)。结论:给予成年期小鼠慢性应激刺激可导致老年期小鼠认知功能损害,其记忆的损害与年龄老化之间可能具有协同作用。     

γ-氨基丁酸对慢性脑缺血致血管性痴呆大鼠学习记忆能力的影响

目的观察γ-氨基丁酸（GABA）对慢性脑缺血致血管性痴呆（VD）大鼠学习记忆能力及海马CA1区神经元形态学的影响。方法将SD大鼠随机分为假手术组、模型组、GABA组,采用双侧颈总动脉永久性结扎法建立VD模型。GABA组术后腹腔注射GABA0.5g.kg-1.d-1,连续注射60d;用Morris水迷宫实验检测大鼠空间学习记忆能力;Nissl染色观察大鼠海马CA1区神经元形态学变化。结果 GABA能明显改善VD大鼠学习记忆能力,也能减轻海马CA1区神经元损伤。结论 GABA能改善慢性脑缺血致VD大鼠的学习记忆能力,减轻海马神经元损伤可能是其机制之一。     

针刺结合运动训练干预脑梗死大鼠海马CA3区微管相关蛋白及突触素表达及学习记忆功能变化

实验观察针刺百会(GV20)、曲鬓(GB 7)和前顶穴(GV21)联合运动训练干预和件下大脑中动脉闭塞大鼠模型大鼠海马CA3区微管相关蛋白2和突触素蛋白的表达,并和单独运动训练干预的大鼠对比。Y型迷宫实验和免疫组织化学染色显示,建模后5周,针刺联合运动训练组穿越Y型迷宫错误次数均少于模型组和运动训练组,针刺联合运动训练组的微管相关蛋白2和突触素表达明显增高,各组海马CA3区的微管相关蛋白2,突触素的表达和穿越Y型迷宫错误次数均呈明显的负相关性。说明针刺联合运动训练可以改善脑梗死大鼠学习和记忆功能,其机制与海马CA3区的树突及突触可塑性有关。     

丁苯酞对慢性脑缺血大鼠海马iNOS及MG表达的影响

目的观察丁苯酞对慢性脑缺血大鼠海马区诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、小胶质细胞(microglia,MG)表达的影响,探讨丁苯酞脑保护作用机制。方法 48只雄性SD大鼠随机分为4组:正常大鼠组为A组,假模型组为B组,模型组为C组,丁苯酞干预组为D组。行双侧大鼠颈总动脉永久结扎的方法制作大鼠慢性脑缺血模型。丁苯酞干预组在慢性脑缺血模型成功后给予丁苯酞软胶囊0.2g·kg~(-1)治疗12周,采用Y迷宫测定各组大鼠学习记忆能力,免疫组化染色测定iNOS及OX42(小胶质细胞的标志)表达,特异性尼氏染色方法测定海马CA1区神经元。结果 A、B组大鼠学习记忆能力正常,海马区iNOS、OX42少量表达,神经元数目正常。C、D组大鼠学习记忆能力下降,海马区iNOS、OX42表达增多,神经元数目减少。与C组相比,D组大鼠学习记忆能力明显增加(P0.01),海马区iNOS、OX42表达减少(P0.01),神经元数目增加(P0.01)。结论丁苯酞可减少慢性脑缺血大鼠海马区iNOS、OX42表达,减少MG的过度激活,减少海马区神经元坏死,提高大鼠的学习记忆能力,具有脑保护作用。     

血管性痴呆小鼠海马胆碱乙酰转移酶mRNA表达特征研究

目的探讨血管性痴呆小鼠海马神经元胆碱乙酰转移酶原位杂交变化特征及其在血管性痴呆发病中的作用。方法双侧颈总动脉线结反复缺血-再灌注法制备模型,利用跳台试验和水迷宫试验观测其行为学改变,采用原位杂交技术观测小鼠海马神经元胆碱乙酰转移酶mRNA的表达变化。结果模型组小鼠学习、记忆成绩较假手术明显降低(P<0.01),其海马胆碱乙酰转移酶mRNA表达也明显下降(P<0.01)。结论血管性痴呆小鼠学习、记忆成绩下降可能与其海马胆碱乙酰转移酶mRNA低水平表达有关。     

宽叶缬草对血管性痴呆小鼠学习记忆及海马区神经元病理学改变的影响

目的:观察宽叶缬草对血管性痴呆模型小鼠学习记忆及海马区神经元病理学改变的影响。方法:采用反复夹闭双侧颈总动脉结合腹腔注射硝普钠的方法复制小鼠拟血管性痴呆的模型。健康昆明小鼠54只,随机分为3组:假手术组、血管性痴呆模型组、宽叶缬草组。分别于术后7、15、30 d,跳台实验检测其痴呆程度;透射电镜、HE和Nissl染色对海马区神经元病理学改变进行观察。结果:宽叶缬草组跳台实验潜伏期明显短于模型组(P<0.01),受电击总时间少于模型组(P<0.01);宽叶缬草组海马CA1区神经元数量明显多于模型组(P<0.01);模型组可见神经元脱失、部分神经细胞核固缩并有胶质细胞增生等病理学改变。结论:宽叶缬草能明显减轻血管性痴呆小鼠海马CA1区神经元损伤,改善脑缺血引起的学习记忆障碍。     

痴呆大鼠模型的行为学、脑内胆碱乙酰转移酶及突触素改变

目的：观察Meynert核损害对大鼠脑内胆碱乙酰转移酶(ChAT)和突触素(P38)的影响。方法：Ibotenic acid定位损伤大鼠脑建立AD模型，利用水迷宫和跳台观察其行为学改变，利用原位杂交、免疫组化及图像分析测定大鼠脑内胆碱乙酰转移酶(ChAT)和突触素的表达。结果：胆碱能损害组大鼠的学习记忆能力低于正常对照组和假手术组，其脑内ChAT和突触素的表达也明显下降。结论：保护中枢胆碱能系统和增加突触素水平有助于改善认知记忆能力。     

慢性间断性缺氧对帕金森病模型小鼠行为学及黑质病理改变的影响

目的：探讨慢性间断性缺氧（CIH）对百草枯诱导的帕金森病（PD）模型小鼠行为学及黑质病理改变的影响。方法：雄性6周龄C57BL／6小鼠44只,随机分为对照组、百草枯组、CIH组和百草枯＋CIH组,通过爬杆实验和自主活动记数检测小鼠行为学变化;苏木精-伊红染色及焦油紫染色和电镜观测黑质多巴胺能神经元形态学及细胞数的变化。结果：①百草枯＋CIH组较其余3组爬杆实验评分、自主活动计数明显减少;②百草枯组、CIH组和百草枯＋CIH组黑质多巴胺能神经元与对照组比较,均出现不同程度的形态学改变,以百草枯＋CIH组最为严重;焦油紫染色：对照组、CIH组、百草枯组和百草枯＋CIH组黑质细胞计数分别为70．09±6．46、38．36±4．34、53．09±4．55和23．18±4．85,3组黑质多巴胺能神经元与对照组比较均出现不同程度的减少,且以百草枯＋CIH组减少最为明显（P〈0．01）。结论：CIH加重了百草枯所致PD模型小鼠行为学及黑质多巴胺能神经元的病理损害。     

Ultrastructure of non-myelinated neurons during energy deprivation

Summary This paper examines the neuropathology of oxygen-glucose deprivation uncomplicated by stagnant conditions. Rabbit vagus nerves were pulled into asmulti-compartment perfusion chamber, stimulated five times per second and deprived of energy by substituting nitrogen and deoxyglucose for oxygen and glucose in the Locke's perfusate. After incubation the compartments were perfused with gluteraldehyde solution, and the nerves were prepared for electron microscopy. Fixation in the compartments ensured precise cross and longitudinal sections which permitted quantitative comparisons. Although the action potentials ceased in 45 min, 1 h of energy deprivation did not significantly affect the ultrastructure. After 2 h of deprivation the axons were smaller and flattened and microtubules appeared packed together. In the smallest axons the microtubules were gone, the neurofilaments were compacted and the few mitochondria had a dense, homogenous appearance. By 4 h the shrinking was extreme, yet 8% were swollen much larger than any of the controls. Longitudinal views showed these balloned areas were greatly expanded regions of the smallest axons. Both tiny and huge regions were devoid of microtubules and the swollen axons contained expanded mitochondria.Calcium is indirectly implicated in the pathogenesis by the concurrence of mitochondrial alteration as the microtubules disappear coupled with the known role of mitochondria in calcium regulation and the reported effect of high calcium on microtubual dissociation. In is suggested that axons first shrink as osmotially active molecules are used or washed out. After a time without energy the mitochondria can no longer regulate the intracellular calcium, microtubules dissociate, and calcium-activated phospholipases create osmotically active molecules. Finally, high-amplitude, disruptive swelling occurs.Supported, in part, by a Grant-in-aid from the American Heart Association with funds contributed by the American Heart Association, Kansas Affiliate and by the University of Kansas Biomedical Sciences Support Grant RR0737     

星形胶质细胞对天冬氨酸特异性半胱氨酸蛋白酶介导β淀粉样蛋白早期突触毒性作用的影响

目的探讨星形胶质细胞(astrocyte,AS)对天冬氨酸特异性半胱氨酸蛋白酶(cysteinyl aspartate specific proteinase,caspase)介导β淀粉样蛋白(β-amyloid,Aβ)早期突触毒性作用的影响,以期为进一步研究与血管性痴呆(vascular dementia,Va D)的发病机制奠定基础。方法以原代培养大鼠海马纯神经元体系(NE-S)及混合培养体系(MIX-S,主要包含神经元及AS)为研究对象,各体系分为6组:对照组、caspase-8抑制剂组、caspase-9抑制剂组、Aβ处理组、caspase-8抑制剂预处理加Aβ组和caspase-9抑制剂预处理加Aβ组。免疫荧光检测各组近胞体10μm段树突中突触后密度蛋白(postsynaptic density-95,PSD95)表达量的变化。结果 1在NE-S与MIX-S中,与对照组相比,caspase-8抑制剂组、caspase-9抑制剂组PSD95的表达量均无明显差异,Aβ处理组PSD95的表达量均显著降低(P均0.001)。2在NE-S中,与Aβ处理组相比,caspase-9抑制剂预处理加Aβ组PSD95的表达量显著回升至对照组水平,caspase-8抑制剂预处理加Aβ组则无显著改变;在MIX-S中的结果则相反,即caspase-8抑制剂预处理加Aβ组PSD95的表达量显著回升至对照组水平,而caspase-9抑制剂预处理加Aβ组则无显著改变。3MIX-S与NE-S两种培养系统间相比较,对照组间及Aβ处理组间PSD95的表达量均无显著差异,而caspase-8抑制剂预处理加Aβ组间及caspase-9抑制剂预处理加Aβ组间PSD95的表达量差异有显著性。结论在Aβ早期突触毒性作用中,AS参与caspase-8介导的死亡受体通路激活过程,且参与抑制神经元的线粒体通路。     

Effects of genistein on neuronal apoptosis, and expression of Bcl-2 and Bax proteins in the hippocampus of ovariectomized rats

Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-2 in the hippocampus of rats decreased and Bax expression increased, with an obvious upregulation of apoptosis. However, intraperitoneal injection of genistein or 17β-estradiol for 15 consecutive weeks from the second day after operation upregulated Bcl-2 protein expression downregulated Bax protein expression, and attenuated hippocampal neuron apoptosis. Our experimental findings indicate that long-term intervention with genistein can lead to a decrease in apoptosis in hippocampal neurons following ovariectomy, upregulate the expression of Bcl-2, and downregulate the expression of Bax. In addition, genistein and 17β-estradiol play equal anti-apoptotic and neuroprotective roles.     

Magnetic resonance morphometry of the loss of gray matter volume in Parkinson’s disease patients

Voxel-based morphometry can be used to quantitatively compare structural differences and functional changes of gray matter in subjects.In the present study,we compared gray matter images of 32 patients with Parkinson’s disease and 25 healthy controls using voxel-based morphometry based on 3.0 T high-field magnetic resonance T1-weighted imaging and clinical neurological scale scores.Results showed that the scores in Mini-Mental State Examination and Montreal Cognitive Assessment were lower in patients compared with controls.In particular,the scores of visuospatial/executive function items in Montreal Cognitive Assessment were significantly reduced,but mean scores of non-motor symptoms significantly increased,in patients with Parkinson’s disease.In addition,gray matter volume was significantly diminished in Parkinson’s disease patients compared with normal controls,including bilateral temporal lobe,bilateral occipital lobe,bilateral parietal lobe,bilateral frontal lobe,bilateral insular lobe,bilateral parahippocampal gyrus,bilateral amygdale,right uncus,and right posterior lobe of the cerebellum.These findings indicate that voxel-based morphometry can accurately and quantitatively assess the loss of gray matter volume in patients with Parkinson’s disease,and provide essential neuroimaging evidence for multisystem pathological mechanisms involved in Parkinson’s disease.     

Development of 18F-labeled radiotracers for neuroreceptor imaging with positron emission tomography

Positron emission tomography (PET) is an in vivo molecular imaging tool which is widely used in nuclear medicine for early diagnosis and treatment follow-up of many brain diseases. PET uses biomolecules as probes which are labeled with radionuclides of short half-lives, synthesized prior to the imaging studies. These probes are called radiotracers. Fluorine-18 is a radionuclide routinely used in the radiolabeling of neuroreceptor ligands for PET because of its favorable half-life of 109.8 min. The delivery of such radiotracers into the brain provides images of transport, metabolic, and neurotransmission processes on the molecular level. After a short introduction into the principles of PET, this review mainly focuses on the strategy of radiotracer development bridging from basic science to biomedical application. Successful radiotracer design as described here provides molecular probes which not only are useful for imaging of human brain diseases, but also allow molecular neuroreceptor imaging studies in various small-animal models of disease, including genetically-engineered animals. Furthermore, they provide a powerful tool for in vivo pharmacology during the process of pre-clinical drug development to identify new drug targets, to investigate pathophysiology, to discover potential drug candidates, and to evaluate the pharmacokinetics and pharmacodynamics of drugs in vivo.     

Differential expression of carboxyl terminal derivatives of amyloid precursor protein among cell lines.

Understanding the pathway for amyloid percursor protein (APP) catabolism has become an important line of investigation. APP is a ubiquitous membrane bound protein that is rapidly cleaved at the membrane, yielding a secreted protein identical to protease nexin II and an internalized 11.5 kDa 100 residue C terminal derivative (CTD). The levels of CTDs in a variety of cell lines have been examined and were found to differ. Cell types associated with the pathology of Alzheimer's disease (AD), such as olfactory neuroblasts (ON) and cortical vascular endothelial cells, have higher levels of CTDs than lymphoblasts and melanoma cells. The mechanism of CTD catabolism appears to involve the lysosome because blockade of lysosomal but not endosomal or mitochondrial function results in increased levels of CTDs. Under these conditions, production of larger, amyloidogenic CTDs is also seen. In cells possessing higher levels of CTDs we find that the mechanism for production of amyloidogenic CTDs may involve the internalization of intact full-length APP. Thus, inhibition of the lysosomal system appears capable of generating amyloidogenic peptides. The amount of amyloidogenic peptides appears to vary among cell lines. Such variation may shed light on why amyloid accumulates around specific cell types such as vascular endothelial cells, neurons, and glia. Finally, disfunction of the lysosomal system may play a role in the pathogenesis of Alzheimer's disease.     

Further validation of the THINC‐it tool and extension of the normative data set in a study of n = 10.019 typical controls

IntroductionWe report further validation and normative data for the THINC‐Integrated Tool (THINC‐it), a measure of cognitive function designed for use with individuals living with Major Depressive Disorder, but which is finding use in further psychiatric and neurological diseases. THINC‐it comprises four objective computerised cognitive tests based on traditional psychological paradigms and a version of the Perceived Deficits Questionnaire assessment.MethodsSample size of n = 10.019 typical control study participants were tested on one to two occasions to further validate the reliability of THINC‐it. Temporal reliability was assessed across 120–180 days.ResultsTest‐retest reliability correlations varied between r = 0.50 and 0.72 for the component measures and r = 0.75 (95% confidence intervals 0.74, 0.76) for the THINC‐it composite score. Normative data categorised by Age, Sex and Years of Education were calculated and the effect on task performance was reported.DiscussionOur analysis confirms previously reported levels of reliability and validates previously reported normative data values.     

Neuroprotective role of fibronectin in neuron-glial extrasynaptic transmission

Most hypotheses concerning the mechanisms underlying Parkinson’s disease are based on altered synaptic transmission of the nigrostriatal system.However,extrasynaptic transmission was recently found to affect dopamine neurotransmitter delivery by anisotropic diffusion in the extracellular matrix,which is modulated by various extracellular matrix components such as fibronectin.The present study reviewed the neuroprotective effect of fibronectin in extrasynaptic transmission.Fibronectin can regulate neuroactive substance diffusion and receptor activation,and exert antineuroinflammatory,adhesive and neuroprotective roles.Fibronectin can bind to integrin and growth factor receptors to transactivate intracellular signaling events such as the phosphatidylinositol 3-kinase/protein kinase B pathway to regulate or amplify growth factor-like neuroprotective actions.Fibronectin is assembled into a fibrillar network around cells to facilitate cell migration,molecule and ion diffusion,and even drug delivery and treatment.In addition,the present study analyzed the neuroprotective mechanism of fibronectin in the pathogenesis of Parkinson’s disease,involving integrin and growth factor receptor interactions,and discussed the possible therapeutic and diagnostic significance of fibronectin in Parkinson’s disease.     

Clinical and molecular research of neuroacanthocytosis

Neuroacanthocytosis is an autosomal recessive or dominant inherited disease characterized by widespread, non-specific nervous system symptoms, or spiculated "acanthocytic" red blood cells. The clinical manifestations typically involve chorea and dystonia, or a range of other movement disorders. Psychiatric and cognitive symptoms may also be present. The two core neuroacanthocytosis syndromes, in which acanthocytosis is atypical, are autosomal recessive chorea-acanthocytosis and X-linked McLeod syndrome. Acanthocytes are found in a smaller proportion of patients with Huntington’s disease-like 2 and pantothenate kinase-associated neurodegeneration. Because the clinical manifestations are diverse and complicated, in this review we present features of inheritance, age of onset, neuroimaging and laboratory findings, as well as the spectrum of central and peripheral neurological abnormalities and extraneuronal involvement to help distinguish the four specific syndromes.     

轻型缺血性卒中静脉溶栓后双重抗血小板疗效观察

目的 观察rt-PA静脉溶栓联合双重抗血小板治疗轻型缺血性卒中的有效性及安全性。 方法 以2013年12月-2016年12月在石家庄市第一医院连续住院治疗的轻型缺血性卒中患者为研究 对象,将其随机分为对照组、溶栓+单抗组和溶栓+双抗组。对照组不进行静脉溶栓,长期口服阿 司匹林（100 mg/d）抗血小板治疗;溶栓+单抗组在rt-PA静脉溶栓（0.9 mg/kg,最大剂量90 mg）基 础上长期单用阿司匹林（100 mg/d）抗血小板治疗;溶栓+双抗组在溶栓后单抗基础上加用氯吡格雷 （75 mg/d）双重抗血小板治疗,双抗治疗21 d后改为阿司匹林长期单抗治疗。随访3个月,有效性指标 为3个月时NIHSS 0～1分、Barthel指数（Barthel index,BI）95～100分和mRS 0～1分的比例,3个月时缺 血性卒中的复发率;安全性指标为治疗24 h出血转化和症状性出血转化的发生率。另外比较三组间 基线和3个月时血清hs-CRP和IL-6的水平差异。 结果 研究共纳入85例患者,对照组28例,溶栓+单抗组28例,溶栓+双抗组29例,全部患者均完 成3个月随访,无死亡患者。对照组、溶栓+单抗组和溶栓+双抗组3个月随访时NIHSS 0～1分比例分 别为46.43%、78.57%和93.10%,BI 95～100分比例分别为53.57%、82.14%和89.66%,mRS 0～1分 的比例分别为50.00%、82.14%和93.10%,三组上述有效性指标差异均有统计学意义,两两比较显 示,溶栓+双抗组高于溶栓+单抗组和对照组,溶栓+单抗组高于对照组,差异均有统计学意义;对 照组、溶栓+单抗组和溶栓+双抗组3个月时缺血性卒中复发率分别为32.14%、7.14%和3.45%,差异 有统计学意义。安全性指标方面,三组均无出血转化事件。对照组、溶栓+单抗组和溶栓+双抗组3 个月时的hs-CRP水平分别为11.92±3.58 mg/L、9.04±2.85 mg/L和6.04±2.65 mg/L,IL-6水平分别为 26.18±4.65 ng/L、16.11±6.93 ng/L和12.84±2.57 ng/L,三组上述炎症因子水平差异均有统计学意 义,其中溶栓+双抗组低于溶栓+单抗组和对照组,溶栓+单抗组低于对照组。 结论 对于急性轻型缺血性卒中患者,rt-PA静脉溶栓治疗后短期双重抗血小板治疗可显著改善患 者神经功能,降低炎症因子水平,降低复发率,且不增加出血风险。