BDNF、NGF对体外长期培养的胚基底前脑胆碱能神经元的影响

本文探讨了脑源性神经营养因子、神经生长因子对体外长期培养的胚基底前脑胆碱能神经元是否具有延缓退变的作用。实验分为脑源性神经营养因子组、神经生长因子组、脑源性神经营养因子加神经生长因子组及单纯对照组。取孕 17d SD大鼠胚基底前脑原基制成细胞悬液接种于 2 4孔培养板中 ,按分组加入含相应神经营养因子和不含神经营养因子的 DMEM培养液 ,分别于体外培养 12、18、2 4、3 0 d后进行乙酰胆碱酯酶组织化学反应。显微镜下计数各孔中乙酰胆碱酯酶阳性神经元数 ,每孔随机测量和计数 2 5个乙酰胆碱酯酶阳性神经元的平均胞体直径、发出的突起数和最长突起长度。数据用方差分析和 SNK检验进行统计学处理。结果显示 ,在培养的 4个时期 ,含脑源性神经营养因子组、神经生长因子组和脑源性神经营养因子加神经生长因子组的各项数据均明显地优于单纯对照组 ;脑源性神经营养因子加神经生长因子组的各项数据 ,特别是最长突起长度优于单独使用脑源性营养因子或神经生长因子组。提示 :脑源性神经营养因子和神经生长因子不仅对体外培养的胚胆碱能神经元发育生长具有促进作用 ,而且还可延缓体外长期培养的大鼠胚基底前脑胆碱能神经元的退变 ;两者的联合使用还可对延缓其退变具有协同作用     

银杏内酯对大鼠基底前脑神经元生长发育的影响

目的：观察银杏内酯对培养的胚胎大鼠基底前脑胆碱能神经元和NADPH-d阳性神经元生长发育的作用。方法：取E17Wistar大鼠胚胎基底前脑进行体外细胞培养，并给予银杏内酯。进行乙酰胆碱酯酶(acetyl cholinesterase，AChE)和NADPH-d酶组织化学染色，并在光镜下进行阳性细胞计数和显微测量胞体及突起发育状况。结果：给予银杏内酯处理后，培养物中乙酰胆碱酯酶阳性神经元和NADPH-d阳性神经元数量均较对照组显著增加，且神经元发育状况好于对照组，胞体大，突起多且长。结论：银杏内酯可以促进体外培养的基底前脑神经元中乙酰胆碱酯酶和NADPH-d的表达，并能促进表达这两种酶的神经元生长发育。     

Neurturin和神经生长因子对体外培养的神经生长因子受体阳性神经元生长发育的影响

目的探讨Neurturin(NTN)、神经生长因子(NGF)对新生大鼠基底前脑胆碱能神经元生长发育的影响。方法用免疫组化结合图象分析技术观察Neurturin和NGF对培养的新生大鼠基底前脑NGF-R阳性神经元生长发育的作用。结果培养4d时,NTN组的NGF-R阳性神经元细胞数目、突起数、胞体面积和最长突起长度均与对照组有显著性差异(P<0.05),NGF+NTN组各项指标均优于NGF组或NTN组(P<0.05);培养8d时,NTN组除突起数目外其他各项指标均与对照组无显著性差异(P>0.05),NGF+NTN组各项指标仍然均优于NGF组或NTN组(P<0.05);NTN组NGF-R阳性神经元突起数多于NGF组(P<0.05)。结论Neurturin对体外培养的新生大鼠基底前脑NGF-R阳性神经元生长发育有营养作用,但作用时间较短,而且增加突起数的作用较NGF强;Neurturin和NGF的联合作用较单独使用Neurturin或NGF为好。     

成年大鼠基底前脑存在一个Nestin免疫阳性神经元簇

目的　观察Nestin免疫活性在成年大鼠基底前脑中的表达和分布 ,并探讨其与胆碱能神经元之间的关系。方法　采用免疫组化方法对成年大鼠基底前脑的切片进行nestin免疫组化染色及其与ChAT ,NADPH d双标染色。结果　在成年大鼠基底前脑的隔斜角带复合体有一个连续的nestin免疫阳性细胞带 ,胞体较大 ,梭形或多极形 ,有 2～ 4个突起。双标染色显示 ,Nestin阳性神经元与ChAT ,NADPH d阳性神经元间杂分布 ,大多数不呈交叉反应 ,只有少数 ,约 10 %呈双标染色。结论　成年大鼠基底前脑存在一个有别于胆碱能神经元的nestin免疫阳性神经元簇 ,其化学属性和生物学意义有待进一步研究。     

Aβ31-35和ApoE4对体外大鼠基底前脑神经元存活和生长的协同作用

目的　探讨 β-淀粉样蛋白 (Aβ)和载脂蛋白 (Apo E4)对基底前脑神经元存活和生长的影响 ,研究Alzheimer病 (AD)发病的细胞分子机制。　方法　体外培养基底前脑神经细胞 ,MTT法和免疫细胞化学方法结合体视学分析 ,观察 Aβ31- 35和 Apo E4对基底前脑神经元存活及胞体和突起生长的影响。　结果　 (1) MTT法测得的 Aβ- 31- 35 Apo E4组的 A值 ,与对照组比较明显减小 (P<0 .0 5 ) ,说明神经元的存活力降低 ,存活数量减少 ;(2 )Aβ31- 35 Apo E4组的神经元胞体最长径和最短径明显低于对照组和 Apo E4组 (P<0 .0 5 ) ;平均突起长度也明显低于对照组、Apo E4组和 Aβ31- 35 (10 μmol/ L)组 (P<0 .0 1) ;(3) Aβ31- 35 (2 0 μm ol/ L)组平均突起长度比对照组、Apo E4组和 Aβ31- 35 (10 μmol/ L)组明显减小 (P<0 .0 1) ;(4) Aβ31- 35 Apo E4组和 Aβ31- 35 (2 0 μm ol/ L)组的胆碱能神经元最长突起长度、总突起长度及平均突起长度均明显低于对照组 (P<0 .0 1) ;且这两组的 Ch AT阳性神经元的胞体平均灰度也明显低于对照组 (P<0 .0 5 ) ,说明 Ch AT的活性下降。单独 Apo E4对基底前脑神经元的存活和生长均无明显影响。　结论　 Aβ31- 35 Apo E4比单独 Aβ31- 35对神经元存活及胞体和突起生长的抑制作     

Genistein对去卵巢大鼠基底前脑胆碱能神经元影响的体内研究

本文旨在研究染料木素(genistein)对去卵巢大鼠基底前脑胆碱能神经元的影响。雌性大鼠双侧卵巢切除2周后用genistein和雌激素替代治疗1周。称子宫重量以确定手术是否成功及雌二醇(E2)的治疗是否有效。用免疫组化染色、RT-PCR和Westernblot等方法对胆碱能神经元数量、ChAT基因和蛋白的表达量进行检测。结果显示:去卵巢3周后子宫变轻,雌激素替代治疗能增加去卵巢子宫的重量,而genistein替代治疗对去卵巢子宫的重量影响不明显;去卵巢3周后,内侧隔核(MS)和斜角带垂直臂核(VDB)内的胆碱能神经元数量、ChAT基因和蛋白的表达量均明显减少,雌激素和genistein替代治疗后能显著增加去卵巢大鼠MS和VDB内的胆碱能神经元数量、ChAT基因和蛋白的表达量。本研究结果提示:genistein对去卵巢大鼠基底前脑胆碱能神经元具有类似雌激素样神经保护作用,而对子宫影响不明显。     

乙酰胆碱酯酶阳性神经元在鼠脑的分布和形态特征

本文用乙酰胆碱酯酶(AChE)再生技术,研究AChE阳性神经元在鼠脑的分布和形态特征。按其染色程度,可见强度、中度和轻度三种染色细胞。强染色细胞多数是较大的多极细胞,主要分布于纹状体、基底前脑、下丘脑、黑质、红核、蓝斑,腹侧被盖区、臂旁核、桥被盖核和脑神经运动核。本文将AChE染色结果和胆碱乙酰转移酶(ChAT)免疫组织化学资料进行了比较,对AChE和胆碱能神经元的关系,以及AChE阳性神经元的性质和意义,进行了讨论。     

BDNF、NGF对体外培养的胚胆碱能神经元生长发育的影响

本文用AChE组化方法，研究了BDNF、NGF对培养的胚鼠基底前脑胆碱能神经元的作用及BDNF和NGF的协同作用。结果表明BDNF和NGF都具有增加AChE阳性神经元数量的作用，二者的不同在于BDNF作用出现的时间较早、强度较小；而NGF作用出现的时间较迟但强度较大。并发现BDNF对体外培养的胚胆碱能神经元胞体早期的生长发育作用比较明显，而NGF的作用则不甚显著。BDNF对胚胆碱能神经元发出突起和突起的延伸作用较NGF强。BDNF和NGF的联合作用较单独使用BDNF或NGF为好。本文的结果提示在体外培养中两种营养因子联合应用较只用一种因子有益。     

γ-干扰素对大鼠胚胎基底前脑及隔区核团胆碱能神经元分化的影响

为了研究γ-干扰素(IFNγ)对大鼠胚胎基底前脑及隔区核团胆碱能神经元分化的作用,采用免疫组织化学方法对胆碱能神经元的特异性标记酶-胆碱乙酰基转移酶(ChAT)进行染色,ChAT阳性细胞的数量反映了胆碱能神经元的数量,并用14C-乙酰CoA作底物来检测ChAT活性。结果显示,IFNγ处理过的实验组,ChAT阳性细胞数量显著增加,ChAT活性也增加,这种增加被大鼠抗小鼠IFNγ单克隆抗体(Ab-IFNγ)完全拮抗。采用流式细胞术对细胞周期进行分析,细胞周期及细胞百分率无明显改变。用MAP2标记神经细胞,神经细胞数基本未增加。以上结果提示:IFNγ不能促进基底前脑和隔区神经元增殖,胆碱能神经元表达增加不是因为神经元数目增加而是分化的结果。     

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。     

IL-1β对培养大鼠胆碱能神经元的影响及机制探讨

目的:探讨IL-1β对大鼠胆碱能神经元的影响及机理。方法:检测不同时相、不同脑区的培养神经细胞AChE、BuchE及ChAT的活性和前脑基底、皮层中胆碱酯酶阳性细胞数目。 结果:IL-1β对AChE活性的最大促进作用时相为24 h,皮层、前脑基底和海马部位的AChE活性明显高于对照组(P＜0.01),且能够完全被IL-1ra所阻断; 而小脑、脊髓、基底神经节部位的AChE活性则未见明显变化,同时各组BuchE、ChAT的活性均无明显变化,前脑基底、皮层中胆碱酯酶阳性细胞数目亦未见明显变化。结论: IL-1β能够明显升高特定脑区AChE活性,使乙酰胆碱的生成减少;而AChE活性的增高可能与其基因的转录和翻译增加有关。     

Neurotrophic effect of brain-derived neurotrophic factor on basal forebrain cholinergic neurons in culture from postnatal rats.

We examined the effect of brain-derived neurotrophic factor (BDNF) on cholinergic neurons in culture from postnatal rat basal forebrain by assay of choline acetyltransferase (ChAT) activity and cytochemical staining for acetylcholinesterase (AChE). BDNF was found to increase the ChAT activities but failed to promote the survival of AChE-positive neurons in cultures from neonatal (P3) rats, suggesting that its main role is cholinergic differentiation. In contrast, an enhancement of the survival of AChE-positive neurons and of ChAT activity was observed in cultures from P15-16 rats, suggesting that BDNF's main action is the maintenance of cholinergic neurons. Our results indicate a similarity between BDNF and nerve growth factor effects on the responses of cholinergic neurons of postnatal rat basal forebrain in culture.     

Selective disarrangement of the rostral telencephalic cholinergic system in heterozygous reeler mice

Reelin (RELN) is a key molecule for the regulation of neuronal migration in the developing CNS. The reeler mice, which have spontaneous autosomal recessive mutation in the RELN gene, reveal multiple defects in brain development. Morphological, neurochemical and behavioral alterations have been detected in heterozygous reeler (HR) mice, suggesting that not only the presence, but also the level of RELN influences brain development. Several studies implicate an involvement of RELN in the pathophysiology of neuropsychiatric disorders in which an alteration of the cholinergic cortical pathways is implicated as well. Thus, we decided to investigate whether the basal forebrain (BF) cholinergic system is altered in HR mice by examining cholinergic markers at the level of both cell body and nerve terminals. In septal and rostral, but not caudal, basal forebrain region, HR mice exhibited a significant reduction in the number of choline acetyltransferase (ChAT) immunoreactive (ir) cell bodies compared with control mice. Instead, an increase in ChAT ir neurons was detected in lateral striatum. This suggests that an alteration in ChAT ir cell migration which leads to a redistribution of cholinergic neurons in subcortical forebrain regions occurs in HR mice. The reduction of ChAT ir neurons in the BF was paralleled by an alteration of cortical cholinergic nerve terminals. In particular, the HR mice presented a marked reduction of acetylcholinesterase (AChE) staining accompanied by a small reduction of cortical thickness in the rostral dorsomedial cortex, while the density of AChE staining was not altered in the lateral and ventral cortices. Present results show that the cholinergic basalo-cortical system is markedly, though selectively, impaired in HR mice. Rostral sub-regions of the BF and rostro-medial cortical areas show significant decreases of cholinergic neurons and innervation, respectively.     

NGF treatment promotes development of basal forebrain tissue grafts in the anterior chamber of the eye

Summary The effects of nerve growth factor (NGF) on developing central cholinergic neurons were studied using intraocular grafts of rat fetal (E17) basal forebrain tissue. Prior to grafting, grafts were incubated in NGF or saline. Transplants were allowed to mature for six weeks, receiving weekly intraocular injections of NGF or saline. Measurements of NGF levels in oculo after one single injection showed that NGF slowly decreases in the anterior chamber fluid, and after one week, low but significant levels were still present in the eye. Following pretreatment with diisopropylfluorophosphate (DFP), the cholinergic neurons in the grafts were analyzed using three morphological markers: antibodies to cholineacetyltransferase (ChAT), antibodies to acetylcholinesterase (AChE Ab) and acetylcholinesterase histochemistry (AChE). The transplants grew well and became vascularized within the first week. The growth of the NGF-treated basal forebrain grafts was significantly enhanced as compared to the growth of the saline-treated grafts evaluated with repeated stereomicroscopical observations directly through the cornea of the etheranaesthetized hosts. The NGF-treated grafts contained almost twice as many cholinergic neurons seen with all the cholinergic markers used, as the salinetreated grafts. However, there was no difference in cholinergic cell density between the two groups. The morphology and size of an individual cholinergic neuron was similar in the two groups. The fiber density as evaluated with AChE-immunohistochemistry did not change after NGF-treatment. The DFP-treatment did not seem to affect the AChE-immunoreactivity since an extensive fiber network was found, whereas almost no fibers were seen using conventional AChE histochemistry. We have demonstrated that in oculo transplantation of basal forebrain is a useful model for examining in vivo effects of NGF on central cholinergic function. The marked volume increase of NGF-treated grafts and the unchanged density of cholinergic cells and terminals suggests, that NGF increases the survival of not only developing cholinergic neurons, but possibly other non-cholinergic neurons and non-neuronal cells as well. These results support the notion that NGF acts as a neurotrophic factor on cholinergic and possibly non-cholinergic cells in the central nervous system