侧脑室注射192-IgG-saporin致痴呆动物模型的实验研究

建立老年性痴呆模型大鼠,并观察其学习记忆能力及基底前脑胆碱能神经元数目的变化。在成年SD大鼠左侧侧脑室注射免疫毒素192-IgG-saporin(2.5μg/5μl),3周后行Y迷宫检测其学习和记忆能力;4周后处死大鼠,采用免疫组化结合图像分析技术观察各组大鼠基底前脑ChAT阳性神经元数目的变化。结果显示:模型组大鼠的学习记忆能力与正常组相比明显下降(P<0.01);模型组基底前脑的内侧隔核(MS)和斜角带垂直部(VDB)胆碱能神经元数目分别减少至正常组的9.70%和14.09%,与正常组相比均明显下降(P<0.01);学习、记忆能力与基底前脑胆碱能神经元数目密切相关。上述结果表明应用192-IgG-saporin免疫毒素能成功建立AD大鼠动物模型,该模型可用于抗痴呆药物的筛选及药效的评价。     

免疫毒素192-IgG-saporin致痴呆动物基底前脑一氧化氮合酶阳性神经元的变化

目的:建立侧脑室注射免疫毒素192-IgG-saporin致痴呆动物模型,观察其学习记忆能力和基底前脑一氧化氮合酶(NOS)阳性神经元的变化。方法:侧脑室注射免疫毒素192-IgG-saporin,行Y迷宫检测,采用NADPH-d组织化学法染色,结合图像分析技术观察大鼠基底前脑NOS阳性神经元数目和形态学参数的变化。结果:模型组大鼠的学习、记忆能力较正常组明显下降。模型组基底前脑内侧隔核(MS)和斜角带垂直支(VDB)NOS阳性神经元数分别减少到正常组的21.62%和17.70%;细胞周长和面积降低,灰度值升高,均有显著性差异。结论:应用192-IgG-saporin免疫毒素可使基底前脑NOS阳性神经元明显减少。     

NSCs移植对AD鼠基底前脑胆碱能神经元和学习记忆能力的影响

目的:探讨神经干细胞(NSCs)移植对侧脑室注射192-IgG-saporin致老年性痴呆(AD)动物模型的治疗作用。方法:24只SD大鼠随机分为正常组,模型组和移植组,每组8只。左侧侧脑室注射192-IgG-saporin5μ(l0.5μg/μl),建立AD动物模型,基底前脑行NSCs移植,Y-迷宫行为检测,NADPH-d组织化学法染色,结合图像分析技术观察各组大鼠基底前脑NOS阳性神经元数目和形态学参数的变化。结果:侧脑室注射192-IgG-saporin1个月,损伤侧基底前脑内侧隔核(MS)和斜角带垂直支(VDB)一氧化氮合酶(NOS)阳性神经元数明显减少,分别减少到正常组的22.43%和28.36%(与正常组相比P<0.01)。移植组NOS阳性神经元数恢复到正常组的70.22%和74.88%(与模型组相比P<0.01)。细胞形态学参数提示,移植组NOS阳性神经元中含有大小不等的未成熟细胞。大鼠的学习记忆能力与基底前脑NOS阳性细胞数呈正相关。结论:NSCs移植对注射192-IgG-saporin致AD鼠基底前脑胆碱能神经元有明显补充和保护作用,可改善大鼠的学习记忆能力。     

神经干细胞移植对老年痴呆模型鼠基底前脑胆碱能神经元和学习记忆能力的影响

目的:探讨神经干细胞移植对老年性痴呆模型鼠基底前脑胆碱能神经元及学习记忆能力的影响.方法:利用无血清培养技术获得新生SD鼠的基底前脑神经干细胞,切断SD大鼠左侧穹隆海马伞,基底前脑注射神经干细胞.4周后行Y迷宫测试学习记忆能力,免疫组化结合图像分析技术观察各组大鼠基底前脑胆碱能神经元变化.结果:损伤组损伤侧的内侧隔核(MS)和斜角带核(VDB)的NGFR阳性神经元大量减少,分别减少59.7%和5 1.4%.NSC移植组损伤侧的NGFR阳性神经元得到补充和保护,MS和VDB细胞数分别下降22.0%和26.1%.同时,NSC移植组损伤侧MS的NGFR阳性神经元的面积、周长显著增大(P＜0.01),灰度显著增加(P＜0.01);损伤侧VDB的NGFR阳性神经元的面积明显增大且灰度明显增加(P＜0.05),周长显著增大(P＜0.01).Y迷宫测试结果显示,NSC移植组大鼠的空间学习能力得到明显改善(P＜0.05),记忆能力得到显著提高(P＜0.01),基底前脑NGFR阳性细胞数与大鼠的空间学习记忆能力呈正相关.结论:神经干细胞移植对老年性痴呆模型鼠基底前脑胆碱能神经元有明显的补充和保护作用,同时大鼠的学习记忆能力得到明显的改善.     

神经干细胞移植对注射192-IgG-saporin致AD动物模型鼠基底前脑ChAT阳性神经元的影响

目的探讨神经干细胞(NSCs)移植对注射192-IgG-saporin致老年性痴呆动物模型鼠基底前脑ChAT阳性神经元的影响。方法将24只成年SD大鼠随机分为正常组、模型组和移植组,每组8只。模型组:左侧侧脑室注射免疫毒素192-IgG-saporin2.5μg/5μL,建立192-IgG-saporin致老年性痴呆动物模型;移植组:动物模型建立后,于基底前脑行神经干细胞移植,4周后行免疫组织化学染色,结合图像分析技术观察各组大鼠基底前脑ChAT阳性神经元数量和形态学参数的变化。结果模型组注射192-IgG-saporin后1个月,观察到注射侧基底前脑内侧隔核(MS)和斜角带垂直支(VDB)ChAT阳性神经元明显减少,分别为正常组的9.70%和14.10%(与正常组相比,P<0.01);移植组ChAT阳性神经元恢复到正常组的71.51%和73.52%(与模型组相比,P<0.01)。细胞形态学参数提示,移植组ChAT阳性神经元中含有大小不等的未成熟细胞。结论神经干细胞移植对192-IgG-saporin致痴呆模型鼠基底前脑ChAT阳性神经元有明显补充和保护作用。     

BDNF和神经干细胞联用对老年痴呆鼠基底前脑胆碱能神经元和学习记忆能力的影响

探讨脑源性神经营养因子(BDNF)和神经干细胞(NSCs)联合应用对老年痴呆大鼠基底前脑胆碱能神经元及大鼠学习记忆能力的影响。利用无血清培养技术获得新生SD鼠的海马NSCs,行BrdU标记。切断SD大鼠左侧穹隆海马伞,基底前脑注射NSCs,同时侧脑室注射BDNF,2周后行nestin和BrdU/NF、BrdU/GFAP免疫荧光双标染色,4周后行Y迷宫测试,免疫组化结合图像分析技术观察各组大鼠基底前脑神经营养因子受体(NGFR)阳性神经元数目变化。结果发现,移植后NSCs能够在宿主体内存活且分化成神经元和胶质细胞;免疫组化结果显示损伤组大鼠胆碱能神经元数在内侧隔阂(MS)和斜角带(VDB)分别减少64.3%和49.3%,较正常组明显下降(P<0.01);移植组神经元数下降34.1%和27.6%较损伤组有改善(P<0.05),但与正常组比较有显著性差异(P<0.05);联合组神经元数减少15.1%和18.6%,与正常组无显著性差异(P>0.05)。Y迷宫测试结果显示,大鼠的学习记忆能力与基底前脑NGFR阳性细胞数呈正相关。提示,BDNF和NSCs移植的联用较单独使用NSCs或BDNF更好地改善老年痴呆大鼠的学习记忆能力。     

Neurturin和NGF联合应用对AD模型鼠基底前脑NGFR阳性神经元的保护作用

本研究目的是探讨neurturin和神经生长因子(NGF)联合应用对穹窿-海马伞(FF)切断后基底前脑胆碱能神经元的保护作用。将这两种因子联合注射到FF切断的大鼠侧脑室,注射一个月后,取脑进行免疫组化结合图像分析方法对内侧隔核(MS)和斜角带核垂直支(VDB)的神经生长因子受体(NGFR)阳性神经元存活情况进行比较分析。结果表明:FF切断一个月后,损伤组损伤侧MS和VDB的NGFR阳性神经元大量减少(分别减少64.8％和51.4％),MS和VDB的NGFR阳性细胞的面积和周长显著降低(P<0.01),OD值显著增高(P<0.01);NGF组损伤侧NGFR阳性神经元受到保护,NGFR阳性经元数显著高于损伤组损伤侧(P<0.01);联合组损伤侧NGFR阳性神经元也受到保护(MS和VDB细胞数分别只下降7.3％和15.4％),与损伤组损伤侧比较NGFR阳性细胞数增加了57.4％和36.0％(P<0.01),也明显高于NGF组(P<0.05);细胞形态学参数明显改善(P<0.05),细胞膜受体含量显著提高(P<0.05)。结果提示,neurturin和NGF联合应用和NGF单独应用均能不同程度地保护基底前脑胆碱能神经元,联合应用效果更佳。     

神经干细胞移植对192-IgG-saporin老年性痴呆模型鼠的学习记忆及海马胆碱能纤维的影响

目的探讨神经干细胞(NSCs)移植对192-IgG-saporin致老年性痴呆模型鼠学习记忆和海马胆碱能纤维再生的影响。方法采用192-IgG-saporin(2.5μg/5μL)侧脑室注射SD大鼠建立痴呆模型后,行基底前脑神经干细胞移植,4周后行Y迷宫检测,并观察大鼠海马胆碱能纤维数的变化。结果Y迷宫检测显示大鼠的学习、记忆能力,模型组(107.38±9.34、3.75±0.71)与正常组比较明显下降(P<0.01),而移植组(75.26±5.33、5.45±0.51)有所改善(P<0.05);免疫组化显示模型组大鼠海马CA1区辐射层和齿状回分子层胆碱能阳性纤维,模型组与正常组比较,CA1辐射层和齿状回分子层纤维密度分别减少到11.07%和12.96%(P<0.01),与正常组比较均而干细胞移植组则分别恢复到正常组的81.39%和75.30%(P>0.05)。结论神经干细胞能促进192-IgG-saporinAD动物模型鼠学习记忆能力的恢复及海马胆碱能纤维的再生。     

Aβ(1-40)及192-IgG-saporin联合作用对大鼠学习记忆以及海马区锥体细胞和胆碱能纤维的影响

目的探讨Aβ(1-40)及192-IgG-saporin联合应用对大鼠学习记忆及海马区锥体细胞及胆碱能纤维的影响。方法采用Aβ(1-40)和192-IgG-saporin侧脑室内注射方法建造老年性痴呆(AD)动物模型。2周后,Y迷宫检测大鼠学习记忆能力并观察海马区形态学变化。结果Y迷宫结果显示联合组,Aβ(1-40)组及192-IgG-saporin组学习记忆能力与正常组均有下降(P<0.05)。刚果红染色阳性结果证明Aβ(1-40)以及联合组海马区内有类老年斑样物质沉积.尼氏染色表明,与正常组和192-IgG-saporin组相比Aβ(1-40)以及联合组,海马区锥体细胞数量均出现减少(P<0.05)。免疫组织化学显示,与正常组以及Aβ(1-40)比较,192-IgG-saporin以及联合组胆碱能纤维数量均出现明显减少(P<0.01)。结论 Aβ(1-40)及192-IgG-saporin联合应用制造的AD模型能够更全面的模拟AD病理特征,是较理想的模型。     

神经生长因子缓释微球移植对AD模型鼠基底前脑ChAT阳性神经元的保护作用

目的观察神经生长因子微球对AD模型鼠基底前脑ChAT阳性神经元的保护作用。方法采用双乳化技术制备神经生长因子缓释微球;切断SD大鼠左侧穹隆海马伞,基底前脑注射神经生长因子缓释微球;4周后,利用免疫组化法观察各组大鼠基底前脑ChAT阳性神经元变化。结果损伤组损伤侧的MS和VDB的ChAT阳性神经元大量减少,分别减少61.9%和51.4%;神经生长因子缓释微球治疗组损伤侧的ChAT阳性神经元得到明显的保护,MS和VDB细胞数分别下降20.60%和20.9%,明显高于损伤组损伤侧的ChAT阳性神经元存活数。结论神经生长因子缓释微球能够成功地将神经生长因子运载到脑内,神经生长因子缓释微球移植对AD模型鼠基底前脑ChAT阳性神经元有明显的保护作用。     

Neuroinflammation not associated with cholinergic degeneration in aged-impaired brain

Degeneration of the cholinergic neurons in the basal forebrain and elevation of inflammatory markers are well-established hallmarks of Alzheimer's disease; however, the interplay of these processes in normal aging is not extensively studied. Consequently, we conducted a neuroanatomical investigation to quantify cholinergic neurons and activated microglia in the medial septum/vertical diagonal band (MS/VDB) of young (6 months) and aged (28 months) Fisher 344 × Brown Norway F₁ rats. Aged rats in this study were impaired relative to the young animals in spatial learning ability as assessed in the Morris water maze. Stereological analysis revealed no difference between aged and young rats in the total numbers of cholinergic neurons, demonstrating that loss of cholinergic neurons is not a necessary condition to observe impaired spatial learning in aged rats. In this same region, the total number of activated microglia was substantially greater in aged rats relative to young rats. Jointly, these data demonstrate that aging is characterized by an increase in the basal inflammatory state within the MS/VDB, but this inflammation is not associated with cholinergic neuron death.     

Nerve growth factor prevents cell death and induces hypertrophy of basal forebrain cholinergic neurons in rats withdrawn from prolonged ethanol intake

We have previously reported that the hippocampal cholinergic fiber network is severely damaged in animals withdrawn from ethanol, and that a remarkable recovery in fiber density occurs following hippocampal grafting, a finding that we suggested to be underpinned by the graft production of neurotrophic factors, which are known to be decreased after ethanol exposure. It is widely accepted that nerve growth factor (NGF) signals the neurons of the brain cholinergic system, including those of the medial septum/vertical limb of the diagonal band of Broca (MS/VDB) nuclei, from which the septohippocampal projection arises. Because neurons in these nuclei are vulnerable to ethanol consumption and withdrawal we thought of interest to investigate, in withdrawn rats previously submitted to a prolonged period of ethanol intake, the effects of intraventricular delivery of NGF upon the MS/VDB cholinergic neurons. Stereological methods were applied to estimate neuron numbers and neuronal volumes in choline acetyltransferase (ChAT)-immunostained and Nissl-stained material. We have found that in ethanol-fed rats there was a significant reduction in the total number of Nissl-stained and cholinergic neurons in the MS/VDB, and that the suppression of ethanol intake further decreased neuron numbers. In addition, the somatic size of ChAT-IR neurons was reduced by ethanol intake, and withdrawal further aggravated neuronal atrophy. NGF treatment prevented the withdrawal-associated loss, and induced hypertrophy, of cholinergic neurons.These findings show that exogenous NGF protects the phenotype and prevents the withdrawal-induced degeneration of cholinergic neurons in the MS/VDB. These effects might be due to the trophic action of NGF upon the basal forebrain cholinergic neurons, including the hippocampal fiber network that conveys this neurotrophin retrogradely to the MS/VDB, and/or upon their targets, that is, the hippocampal formation neurons.     

Age-related changes in rostral basal forebrain cholinergic and GABAergic projection neurons: relationship with spatial impairment

Both cholinergic and GABAergic projections from the rostral basal forebrain contribute to hippocampal function and mnemonic abilities. While dysfunction of cholinergic neurons has been heavily implicated in age-related memory decline, significantly less is known regarding how age-related changes in codistributed GABAergic projection neurons contribute to a decline in hippocampal-dependent spatial learning. In the current study, confocal stereology was used to quantify cholinergic (choline acetyltransferase [ChAT] immunopositive) neurons, GABAergic projection (glutamic decarboxylase 67 [GAD67] immunopositive) neurons, and total (neuronal nuclei [NeuN] immunopositive) neurons in the rostral basal forebrain of young and aged rats that were first characterized on a spatial learning task. ChAT immunopositive neurons were significantly but modestly reduced in aged rats. Although ChAT immunopositive neuron number was strongly correlated with spatial learning abilities among young rats, the reduction of ChAT immunopositive neurons was not associated with impaired spatial learning in aged rats. In contrast, the number of GAD67 immunopositive neurons was robustly and selectively elevated in aged rats that exhibited impaired spatial learning. Interestingly, the total number of rostral basal forebrain neurons was comparable in young and aged rats, regardless of their cognitive status. These data demonstrate differential effects of age on phenotypically distinct rostral basal forebrain projection neurons, and implicate dysregulated cholinergic and GABAergic septohippocampal circuitry in age-related mnemonic decline.     

Effects of engrafted neural stem cells in Alzheimer's disease rats

Cell therapy is thought to have a central role in restorative therapy, which aims to restore the function of the damaged nervous system. Neural stem cells (NSCs) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the therapeutic effects of transplanting NSCs into rats which have the animal model of Alzheimer's disease (AD). NSCs from the hippocampus and NSCs-derived glial cells labeled with 5′-Bromo-2′-deoxyuridine (BrdU) were transplanted into two groups of transected rat basal forebrain. Nestin staining, glial fibrillary acidic protein (GFAP) staining and double-labeling immunofluorescence were used to detect the engrafted cells in the basal forebrain. Immunohistochemical detection of p75^NGFR showed that the number of cholinergic neurons of the NSCs-transplanted group was significant higher than that of the glia-transplanted group in medial septum (MS) and vertical diagonal branch (VDB) (P < 0.05). Learning and memory abilities were also measured by Y-maze test. The results indicate that transplanted NSCs can differentiate into cholinergic neurons, which may play an important role in the therapeutic effects of transplanted NSCs.