海马注射Aβ25-35对大鼠CA1区tau蛋白和MAP2影响的研究

目的采用β-淀粉样蛋白（β-amyloid,Aβ）25—35注射法建立Alzheimer病（Alzheimer disease,AD）大鼠模型,观察该AD模型中tau蛋白和微管相关蛋白2（microtubule-associated protein-2,MAP2）表达情况。方法将健康雄性Wistar大鼠随机分成健康对照组、假手术组及AD模型组,以凝聚状态的Ap25—35经大鼠右侧海马注射制作AD模型,造模2周后应用HE染色和免疫组化方法,观察AD模型鼠脑中海马CA1区病理形态以及tau蛋白和MAP2的表达。结果AD模型组大鼠海马CA1区锥体细胞层紊乱、变稀、中断、数量减少,同时可见许多细胞体积缩小,胞核固缩且染色加深。AD模型鼠海马CA1区AD模型组tau蛋白阳性细胞（62．13±4．12）个／HP,较健康对照组[（26．78±3．46）个／HP3与假手术组[（26．36±3．13）个／HP]明显增高（均P〈0．01）;MAP2阳性细胞吸光度值AD模型组为5．13±4．12,较健康对照组（28．78±3．46）与假手术组（29．36±3．13）明显减少,差异有统计学意义（均P〈0．01）。结论在AB诱导的AD模型中tau蛋白表达增高,MAP2表达减低。     

血管性痴呆小鼠海马ERK2及p-ERK的表达特征

目的观察血管性痴呆（VD）小鼠海马中细胞外信号调节激酶（ERK2、p-ERK）的表达变化,探讨其在VD发病中的作用机制。方法采用双侧颈总动脉反复缺血-再灌注法制备小鼠VD模型,设立假手术组作为对照。术后第29、30天,经跳台试验和水迷宫试验对各组小鼠进行行为学成绩测试,用免疫组化方法观察各组小鼠海马CA1区ERK2及海马CA3区p-ERK的表达变化。结果VD模型小鼠学习、记忆成绩较假手术组显著下降（P〈0.05）;模型组小鼠海马CA1区ERK2的表达及海马CA3区p-ERK的表达较假手术组减少,差异有统计学意义（P〈0.05）。结论海马神经元内ERK的表达减少可能参与了血管性痴呆的发病机制,因此应用能促进ERK表达的药物可能成为治疗VD的有效方法之一。     

血管性痴呆小鼠海马细胞外信号调节激酶表达的变化

目的:观察血管性痴呆(VD)小鼠海马中细胞外信号调节激酶(ERK1、p-ERK)的表达特征,探讨其在VD发病中的作用机制。方法:采用双侧颈总动脉反复缺血-再灌注法制备小鼠VD模型,设立假手术组作为对照。术后第29、30天,经跳台试验和水迷宫试验对各组小鼠进行行为学成绩测试,用免疫组化方法观察各组小鼠海马CA1区ERK1及海马CA3区p-ERK的表达变化。结果:VD模型小鼠学习、记忆成绩较假手术组显著下降(P<0.05)。模型组小鼠海马CA1区ERK1的表达及海马CA3区p-ERK的表达较假手术组减少,均有显著性差异(P<0.05)。结论:海马神经元内ERK的表达减少可能参与了血管性痴呆的发病机制,因此应用能促进ERK表达的药物可能成为治疗VD的有效方法之一。     

促红细胞生成素对血管性痴呆大鼠行为学及脑组织形态学的影响

目的永久性结扎双侧颈总动脉（2-VO）建立血管性痴呆（VaD）动物模型,观察EPO治疗对VaD大鼠行为学及脑组织形态学的影响。方法选用14～15月龄Wistar大鼠,应用水迷宫进行空间定向学习训练,将达到学会标准者随机分为3组：假手术（Sham）组、VaD组、VaD＋EPO腹部皮下注射治疗（EPO）组。2-VO制作VaD模型,应用水迷宫检测空间定向学习能力;行HE染色,透射电镜观察海马组织病理学变化。结果与Sham组比较,VaD组、EPO组2-VO后8周学习记忆能力均明显下降;VaD组2-VO术后8周海马CA1区锥体神经元细胞稀疏、肿胀,与VaD组相比,EPO组脑组织损伤程度明显减轻,学习记忆能力增强。结论2-VO可引起大鼠学习记忆能力下降,EPO治疗的VaD大鼠学习记忆能力明显增强;海马CA1区神经元的缺血损伤减轻可能是EPO改善VaD大鼠认知功能障碍的组织病理学基础。     

血管性痴呆小鼠海马组织学改变及乙酰胆碱酯酶活性变化特征

目的:探讨血管性痴呆(VD)小鼠海马组织病理学改变及乙酰胆碱酯酶病理(AchE)活性的变化特征.方法:将50只小鼠随机分为假手术组和模型组。模型组采用双侧颈总动脉反复缺血再灌注法制备VD模型,术后第29天和第30天测试学习记忆成绩,术后第30天检测海马CA1区组织学变化及AchE含量。结果:VD模型组小鼠学习记忆成绩较假手术组明显下降;海马CA1区锥体细胞数目减少,细胞核体积变小;且模型组小鼠海马AchE活性明显低于假手术组(P<0.01)。结论:小鼠海马组织内的AchE活性下降参与了VD的形成,进一步导致VD小鼠的学习和记忆障碍。     

盐酸多奈哌齐对血管性痴呆小鼠海马ERK1及ERK2表达变化的影响

目的:探讨盐酸多奈哌齐对血管性痴呆(VD)小鼠海马中细胞外信号调节激酶(ERK1、ERK2)表达变化的影响。方法:采用双侧颈总动脉反复缺血-再灌注法制备小鼠VD模型。将小鼠随机分为假手术组、模型组及药物组,药物组给予盐酸多奈哌齐灌胃治疗。术后第29、30天,经跳台试验和水迷宫试验对各组小鼠进行行为学成绩测试,用免疫组化方法观察各组小鼠海马CA1区ERK1、ERK2的表达变化。结果:盐酸多奈哌齐明显改善了VD小鼠学习、记忆成绩(p<0.05)。模型组小鼠海马CA1区ERK1、ERK2表达较假手术组及治疗组减少,均有显著性差异(p<0.05)。结论:ERK1、ERK2的表达减少可能参与了血管性痴呆的发病机制,盐酸多奈哌齐通过增加乙酰胆碱含量,后者作用于毒蕈碱乙酰胆碱受体(M受体)激活ERK,有助于改善学习和记忆功能。     

纳洛酮对铝致学习记忆减退大鼠海马锥体细胞凋亡的影响

目的观察纳洛酮对铝致学习记忆减退大鼠海马锥体细胞凋亡的影响。方法采用慢性氯化铝灌胃方法,制备学习记忆减退大鼠模型后随机分为模型组和纳洛酮治疗组,另设正常对照组。纳洛酮治疗组大鼠连续7 d腹腔注射纳洛酮。采用脱氧核苷酸末端转移酶介导的脱氧尿苷酸-生物素切口末端标记法,原位检测凋亡细胞,流式细胞仪检测凋亡率。结果纳洛酮组大鼠海马锥体细胞的凋亡率为（6.4&#177;1.6）%,模型组（9.6&#177;1.9）%,差异有统计学意义（P〈0.05）;纳洛酮组大鼠凋亡细胞数为（7.5&#177;1.9）,模型组（12.8&#177;2.2）,差异有统计学意义（P〈0.05）。结论纳洛酮能减少铝致学习记忆减退大鼠海马锥体细胞的凋亡。     

盐酸多奈哌齐对血管性痴呆小鼠海马CA1区Calpain 1表达的影响

目的 探讨盐酸多奈哌齐对反复脑缺血-再灌注后血管性痴呆(VaD)小鼠海马CA1区Calpain 1表达的影响.方法 采用双侧颈总动脉反复缺血-再灌注合并尾端放血的方法制备VaD动物模型.分别于术后第4周和第8周测试小鼠的学习和记忆成绩,应用免疫组化方法观察海马CA1区Calpain 1表达的变化及盐酸多奈哌齐对其的影响.结果 术后4周和8周时模型组小鼠的学习、记忆成绩均明显劣于假手术组小鼠(P<0.01),海马CA1区Calpain 1表达分别是(0.090 0±0.010 0)和(0.102 0±0.008 4),显著高于假手术组的(0.033 2±0.004 3)和(0.031 7±0.004 6)(P<0.01).多奈哌齐治疗组小鼠在术后4周和8周时学习记忆能力较模型组显著改善(P<0.01),海马CA1区Calpain 1表达各为(0.052 0±0.008 4)和(0.068 0±0.008 4),显著低于模型组小鼠(P<0.05).结论 Calpain 1可能参与了脑缺血再灌注后小鼠VaD的发生,盐酸多奈哌齐改善VaD小鼠学习和记忆的能力可能与其减少Calpain 1表达有关.     

盐酸多奈哌齐对血管性痴呆模型小鼠海马神经元ERK表达的影响

目的探讨盐酸多奈哌齐对血管性痴呆(VD)模型小鼠海马神经元中细胞外信号调节激酶(ERK)表达的影响。方法采用双侧颈总动脉反复缺血-再灌注法制备小鼠VD模型。将小鼠随机分为假手术组、模型组及盐酸多奈哌齐治疗组,药物组给予盐酸多奈哌齐灌胃治疗。术后第29、30天,采用跳台试验和水迷宫试验对各组小鼠进行行为学成绩测试,采用免疫组化法观察各组小鼠海马神经元ERK表达的变化。结果盐酸多奈哌齐可明显改善VD模型小鼠学习、记忆成绩(P<0.05)。模型组小鼠海马CA1区ERK1、ERK2表达及海马CA3区p-ERK表达较假手术组及治疗组减少(均P<0.05)。结论盐酸多奈哌齐通过增加乙酰胆碱含量,后者作用于毒蕈碱乙酰胆碱受体(M受体)激活ERK,从而有助于改善学习和记忆功能。海马神经元内ERK的表达减少可能参与了VD的发病机制。     

双氢麦角碱对血管性痴呆小鼠海马乙酰胆碱酯酶活性变化的影响

目的探讨双氢麦角碱对血管性痴呆（VD）小鼠海马组织乙酰胆碱酯酶（AchE）活性变化的影响。方法将75只小鼠随机分为假手术纽、模型组和药物纽。药物组和模型组采用双侧颈总动脉反复缺血再灌注法制备VD模型，术后第29天和第30天测试学习记忆成绩，术后第30天检测海马AchE含量，并研究双氢麦角碱对二者的影响。结果（1）模型组小鼠学习记忆成绩较假手术组明显下降（P〈0．01），治疗组小鼠学习记忆成绩明显优于模型组小鼠（P〈0．01）；（2）模型组小鼠海马AchE活性较假手术组明显降低（P〈0．01），治疗组小鼠海马AchE活性显著高于模型组小鼠（P〈0．05）。结论双氢麦角碱能改善VD小鼠的学习记忆功能，提高海马组织内的AchE活性。     

视频脑电图在小儿癫痫诊断中的应用

目的评价视频脑电图(video-EEG)在小儿癫诊断中的应用价值。方法对126例具有发作性症状的患儿进行连续8h的包括清醒、睡眠、诱发试验及必要的认知测验的视频脑电图监测。结果经发作期视频脑电图证实,39例初诊为癫性发作的患儿中14例(35%)为非癫性发作;15例其他症状发作中13例(86%)为非癫性发作。64例样放电患儿中51例(80%)确定发作类型,22例(34%)确定癫类型。视频脑电图可发现短暂轻微的癫发作及样放电引起的一过性认知损伤。结论视频脑电图在排除非癫性发作、确定癫性发作的类型、评价脑电-临床关系方面可提供准确可靠的证据,进一步提高癫的临床诊断水平。     

Role of glutathione in repair of free radical damage in hippocampus in vitro.

Depletion of glutathione (GSH), an intrinsic antioxidant, increases vulnerability to free radical damage in a number of cell systems. This study investigates the role of GSH in limiting electrophysiological damage and/or recovery from free radical exposure in slices of guinea pig hippocampus. Synaptic potentials (PSPs) and population spikes (PSs) were recorded from field CA1. Free radicals were generated from 0.006% peroxide through the Fenton reaction. Analysis of the input-output curves showed that peroxide treatment decreased PSPs and impaired ability of the PSPs to generate PSs as previously reported. Recovery was nearly total within a half hour. Treatment with 5 mM buthionine sulfoximine (BSO) for 2 h depleted hippocampal GSH to 79.2% of control values. The extent of free radical damage was not increased. Recovery, however, was only partial. GSH was further depleted by oxidation with diamide or covalent bonding with dimethyl fumarate (DMF) immediately before and during the peroxide treatment. Neither diamide nor DMF treatment in BSO-incubated tissue enhanced peroxide-induced electrophysiological deficits. Following these treatments, however, tissue showed little recovery from free radical damage. We conclude that glutathione is essential for repair processes in hippocampal neurons exposed to oxidative damage.     

Neuroprotective properties of memantine in different in vitro and in vivo models of excitotoxicity

The pathogenesis of stroke, trauma and chronic degenerative diseases, such as Alzheimer's disease (AD), has been linked to excitotoxic processes due to inappropriate stimulation of the N-methyl-D-aspartate receptor (NMDA-R). Attempts to use potent competitive NMDA-R antagonists as neuroprotectants have shown serious side-effects in patients. As an alternative approach, we were interested in the anti-excitotoxic properties of memantine, a well-tolerated low affinity uncompetitive NMDA-R antagonist presently used as an anti-dementia agent. We explored in a series of models of increasing complexity, whether this voltage-dependent channel blocker had neuroprotective properties at clinically relevant concentrations. As expected, memantine protected neurons in organotypic hippocampal slices or dissociated cultures from direct NMDA-induced excitotoxicity. However, low concentrations of memantine were also effective in neuronal (cortical neurons and cerebellar granule cells) stress models dependent on endogenous glutamate stimulation and mitochondrial stress, i.e. exposure to hypoxia, the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) or a nitric oxide (NO) donor. Furthermore, memantine reduced lethality and brain damage in vivo in a model of neonatal hypoxia-ischemia (HI). Finally, we investigated functional rescue (neuronal capacity to migrate along radial glia) by memantine in cerebellar microexplant cultures exposed to the indirect excitotoxin 3-nitropropionic acid (3-NP). Potent NMDA-R antagonists, such as (+)MK-801, are known to block neuronal migration in microexplant cultures. Interestingly, memantine significantly restored the number of neurons able to migrate out of the stressed microexplants. These findings suggest that inhibition of the NMDA-R by memantine is sufficient to block excitotoxicity, while still allowing some degree of signalling.     

Storage of lipofuscin in neurons in mucopolysaccharidosis

Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.Supported by a grant from the Expressen Prenatal Research Foundation