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。     

康复新对去卵巢大鼠学习记忆能力和基底前脑胆碱能神经元的影响

目的 探讨康复新对去卵巢大鼠的学习记忆能力的影响及其可能机制.方法 3月龄健康雌性SD大鼠36只,随机分成4组,即假手术组、去卵巢对照组、康复新低剂量组和康复新高剂量组,分别进行干预.8周后用Y迷宫检测大鼠的空间学习记忆能力,用免疫组化染色检测大鼠基底前脑不同区域胆碱能神经元的数目.结果 康复新高剂量组大鼠"学会"所需总训练次数、训练错误次数及记忆检测时错误反应次数与去卵巢对照组比较明显减少(P＜0.05),与假手术组相比差异无统计学意义(P＞0.05);康复新液高、低剂量组大鼠基底前脑内侧隔核(MS)、斜角带核垂直支(vDB)和水平支(hDB)的ChAT阳性神经元数量增多;高剂量组基底前脑各区的ChAT阳性神经元数明显高于去卵巢对照组(P＜0.05),与假手术组相比差异无统计学意义(P＞0.05);而且康复新高剂量组大鼠vDB和hDB的ChAT阳性神经元数明显高于康复新低剂量组(P＜0.05).结论 康复新液可显著改善去卵巢大鼠学习记忆能力,其作用可能是通过增加基底前脑胆碱能神经元的功能实现的;康复新液有望成为防治雌激素撤退引起的神经功能障碍的药物.     

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。     

摘除松果体对大鼠学习记忆及基底前脑胆碱能系统的影响

目的　探讨松果体功能减退对大鼠学习记忆及基底前脑胆碱能系统的影响。方法　选用 3月龄SD大鼠 2 4只 ,随机分为对照组、去松果体组和褪黑素 (MT)组。手术摘除松果体。饲养 1个月后用Morris水迷宫测试学习记忆功能 ,同时用组织化学和免疫组化方法测定海马、前额叶皮质AchE纤维和内侧隔核、斜角带核的ChAT神经元的数量。结果　与对照组比较 ,去松果体组逃避潜伏期明显增加 ,海马、前额叶皮质AchE纤维数量明显减少 ,但内侧隔核、斜角带核的ChAT神经元数量变化不明显。结论　大鼠去松果体可引起大鼠学习记忆能力减弱 ,这可能与基底前脑胆碱能神经元的功能下降有关     

去卵巢后大鼠基底前脑NOS阳性神经元的变化及雌激素的作用

目的　研究基底前脑NOS阳性神经元在大鼠去卵巢之后的时程变化 ,为雌激素类药物替代防治绝经后老年性痴呆提供理论依据。方法　将 6 9只 3月龄雌性大鼠随机分为假手术组、去卵巢对照组及雌激素替代治疗组 ,各 2 3只 ,分别在术后 3d、1周、2周、4周、8周处死 ,脑切片用NADPH d组化方法染色 ,观察并和计数基底前脑各区NOS阳性神经元 ,并进行统计分析。结果　各组大鼠基底前脑各区NOS阳性神经元数目在去卵巢后先上升 ,2周时达到高峰 ,以后假手术组及雌激素替代组NOS阳性神经元数目逐渐下降 ,8周时达正常水平。去卵巢对照组斜角带核水平支及垂直支NOS阳性神经元数目却保持较高水平 ,在 8周时与假手术组及雌激素替代治疗组之间差异有显著性 (P <0 0 1)。结论　去卵巢后基底前脑NOS阳性神经元表达增加 ,而雌激素替代治疗对其有保护作用。     

秋水仙碱对基底前脑巢蛋白阳性和阴性胆碱能神经元的影响

目的:通过研究侧脑室注射秋水仙碱前后基底前脑巢蛋白阳性和阴性胆碱能神经元变化,探讨巢蛋白表达对基底前脑神经元机能的影响及其可能机制。方法:成年健康雌性SD大鼠随机分为正常对照组和侧脑室注射秋水仙碱组,术后分别于24 h、48 h、3 d、7 d、14 d和28 d取脑行冷冻切片与免疫组织化学显色,比较秋水仙碱注射后不同时间点基底前脑巢蛋白~+和巢蛋白~-胆碱能神经元的数目变化。结果:大鼠侧脑室秋水仙碱注射后24 h,基底前脑的内侧隔核(MS)、斜角带核垂直支(vDB)和水平支(hDB)的巢蛋白~+和巢蛋白的胆碱能神经元数目都急骤下降。随着时间的推移巢蛋白~+神经元数目逐渐恢复,术后14 d,巢蛋白~+神经元数目基本恢复至正常水平,但巢蛋白~-胆碱能神经元数目一直维持较低水平。结论:侧脑室注射秋水仙碱后,基底前脑巢蛋白~+和巢蛋白~-的胆碱能神经元都急骤减少,但巢蛋白~+神经元在减少后可逐渐恢复,而巢蛋白~-神经元则不能恢复。     

Nestin在成年大鼠基底前脑表达的鉴定

目的鉴定巢蛋白(Nestin)在成年大鼠基底前脑的表达。方法应用小鼠抗大鼠Nestin单克隆抗体(Rat401)对成年大鼠基底前脑进行了免疫组织化学研究和Westen-blot检测。结果Nestin免疫反应阳性神经元广泛分布于成年大鼠基底前脑的隔-斜角带(MS-DBB)复合体,基底前脑MS-DBB复合体的内侧隔核(MS)、斜角带垂直支(vDB)和斜角带水平支(hDB)分别有一相对分子质量约为240000的单一蛋白带。结论成年大鼠基底前脑MS、vDB和hDB均存在Nestin表达。     

成年大鼠基底前脑nestin阳性神经元的性别差异

为了探讨成年雌雄大鼠基底前脑nestin阳性神经元的性别差异及其意义,本实验应用免疫组织化学方法对正常成年雌雄SD大鼠及去势2周和4周的雌雄SD大鼠基底前脑的内侧隔核(MS)、斜角带垂直支(vDB)及斜角带水平支(hDB)的nestin阳性神经元的变化进行了比较研究。结果显示正常雌雄大鼠MS、vDB及hDB的nestin阳性神经元数十分接近(P>0.05);而去睾丸2周大鼠组MS、vDB、hDB的nestin阳性神经元数则明显高于去卵巢2周大鼠组(P<0.05,P<0.01);去睾丸4周大鼠组vDB、hDB的nestin阳性神经元数依然明显高于去卵巢4周大鼠组(P<0.05),但两组MS间的nestin阳性神经元数差别不大(P>0.05);各组大鼠的nestin阳性神经元的胞体和树突均相似。以上结果表明,正常成年雌雄大鼠基底前脑的nestin阳性神经元数不存在性别差异,无论去势与否,nestin阳性神经元的形态始终不存在性别差异;而去势后nestin阳性神经元数却存在着明显的性别差异。提示基底前脑nestin阳性神经元的性别差异不仅与雌激素和雄激素在雌雄个体中所发挥的不同作用密切相关,而且还可能是促使学习记忆出现性别差异的形态学基础。     

雌激素对去卵巢大鼠基底前脑胆碱能神经元及一氧化氮合酶阳性神经元的影响

目的　探讨雌激素补充治疗对去卵巢大鼠胆碱能神经元及一氧化氮合酶 (NOS)阳性神经元表达的影响及剂量效应关系。方法　 2 0只去卵巢SD大鼠分成 4个不同剂量组 :0 μg(对照组 )、2 0 μg(0 0 8mg/kg)、5 0 μg(0 2 0mg/kg)、10 0 μg(0 4 0mg/kg)组 ;1周后 ,用乙酰胆碱转移酶 (ChAT)免疫化学方法及尼克酰胺腺嘌呤二核苷酸黄递酶 (NADPH d)组织化学方法研究。结果　NOS阳性神经元在内侧隔核 (MS) ,其数目在各组间无明显差异 (P >0 0 5 )。在斜角带垂直支 (VDB) ,5 0 μg剂量组与对照组相比有明显差异 (P <0 0 5 ) ;ChAT阳性神经元在内侧隔核 (MS) ,其 2 0 μg、5 0 μg剂量组数目出现剂量递增效应 ,与对照组比较有明显差异 (P <0 0 5 ) ,但 10 0 μg剂量组与对照组比较没有明显差异 (P >0 0 5 ) ,同时 5 0 μg与 10 0 μg剂量组比较有明显差异 (P <0 0 5 )。ChAT阳性神经元在斜角带水平支 (HDB) ,各组间均无明显差异 (P >0 0 5 )。结论　雌激素补充治疗能选择性影响基底前脑各亚区NOS和胆碱能神经元 ,并有可能影响学习和记忆能力。     

雌激素对去卵巢大鼠基底前脑NOS及Nestin阳性神经元的影响

目的 观察雌激素替代对去卵巢大鼠基底前脑一氧化氮合酶(NOS)及巢蛋白(Nestin)阳性神经元的影响。方法 将28只健康成年雄性SD大鼠随机分为4个处理组:去势24 h雌激素替代组、去势2周雌激素替代组、去势植物油替代组及假手术组。用组织化学及免疫组织化学染色方法观察基底前脑的内侧隔核(MS)、斜角带垂直支(vDB)及水平支(hDB)的NOS和Nestin阳性神经元数的变化。结果 去势行植物油替代可使MS、vDB的NOS阳性神经元数明显下降(P<0.01);去势24 h或2周行雌激素替代均可使以上亚区的NOS阳性神经元数明显升高至正常水平(P<0.01)。去势行植物油替代或雌激素替代对hDB的:Nestin阳性神经元数的影响趋势与NOS阳性神经元的相似(P<0.01),但对MS及vDB的Nestin阳性神经元数影响不大(P>0.05)。结论 去卵巢行雌激素替代可选择性地使基底前脑不同亚区NOS、Nestin阳性神经元数升高,这可能与雌激素高调了NOS和Nestin的表达有关。     

成年大鼠基底前脑隔-斜角带复合体的巢蛋白免疫阳性神经元至海马的纤维投射

目的 观察大鼠基底前脑巢蛋白(nestin)免疫阳性神经元的纤维投射。方法 先用荧光素逆行追踪法显示基底前脑内投射至海马的荧光素标记神经元，观察摄片后再进行nestin免疫组织化学染色。对比荧光照片和免疫组织化学染色照片，辨认荧光素和nestin双标神经元。结果 在基底前脑注射侧的内侧隔核(MS)和斜角带核的垂直支(vDB)和水平支(hDB)均存在荧光素标记细胞，其中一部分为nestin免疫阳性。在MS、vDB和hDB，双标细胞占逆行标记细胞的比例分别为21．3％、25％和20．6％；占nestin阳性细胞的比例分别为26．6％、15．7％和16．3％。结论 大鼠基底前脑的nestin免疫阳性神经元发出神经纤维向海马投射。提示在基底前脑有一个平行于隔-海马胆碱能投射和GABA能投射的第3条通路。     

剥夺卵巢雌激素对成年大鼠基底前脑神经元表达Nestin的影响

目的 探讨剥夺卵巢雌激素对成年大鼠基底前脑神经元表达Ｎｅｓｔｉｎ的影响。方法 将健康成年雌性大鼠随机分为正常对照、卵巢切除２周及４周三组,用免疫组化法观察卵巢切除后基底前脑的内侧隔核（ＭＳ）、斜角带垂直支（ｖＤＢ）及水平支（ｂＤＢ）Ｎｅｓｔｉｎ免疫反应阳性（Ｎｅｓｔｉｎ－ＩＲ） 神经元的形态和数目变化。结果 卵巢切除２周、４周组ＭＳ、ｖＤＢ及ｈＤＢ的Ｎｅｓｈｎ－ＩＲ神经元形态与正常对照组相比无明显变化;但卵巢切除２周、４周组ＭＳ、ｖＤＢ及ｈＤＢ的 Ｎｅｓｔｉｎ－ＩＲ神经元的数目与正常对照组相比均有不同程度的减少,尤以ｈＤＢ的减少最明显（Ｐ＜０．０１,Ｐ＜０．０５）。结论 提示基底前脑Ｎｅｓｔｉｎ－ＩＲ神经元的Ｎｅｓｈｎ表达受卵巢雌激素的影响,ｈＤＢ的Ｎｅｓｈｎ－ＩＲ神经元的表达受此影响更大。     

A decrease in size and number of basal forebrain cholinergic neurons is paralleled by diminished hippocampal cholinergic innervation in mice lacking leukocyte common antigen-related protein tyrosine phosphatase activity

The leukocyte common antigen-related (LAR) receptor, composed of an extracellular region with three immunoglobulin-like and eight fibronectin type III-like domains, and a cytoplasmic region containing two protein tyrosine phosphatase domains, is thought to play a role in axonal outgrowth and guidance during neural development. LAR mutant mice were generated completely lacking the two cytoplasmic protein tyrosine phosphatase domains, resulting in the loss of ability to bind intracellular associating proteins, but (may be) still containing the ability to perform extracellular functions. A reduction in size of basal forebrain cholinergic neurons and diminished hippocampal innervation reported for knockout mice that contain a leaky gene trap inserted into the 5' part of the LAR gene [Yeo T. T. et al. (1997) J. Neurosci. Res. 47, 348-360] warranted a computer-assisted quantitative image analysis throughout the basal forebrain and hippocampus of our LAR mutant mice. The total number, longest diameter and cell body area were calculated for the choline acetyltransferase-positive neurons in the medial septum and vertical diagonal band, and optical density measurements were performed to determine the extent of acetyl cholinesterase-positive fibre innervation of the different layers in the dentate gyrus. In LAR mutant mice, the number of cholinergic cells was significantly reduced (approximately 25%) in the vertical diagonal band. Also, the cross-sectional area of the cholinergic neurons in the medial septum and vertical diagonal band was reduced (5%). These findings were paralleled by a diminished cholinergic innervation of the supragranular (18%) and molecular (4%) layers of the dentate gyrus. Thus, LAR protein tyrosine phosphatase activity appears crucial for size, number and target projection of basal forebrain cholinergic neurons, further strengthening a role for LAR in CNS development.     

Estrogen binding and estrogen receptor characterization (ERalpha and ERbeta) in the cholinergic neurons of the rat basal forebrain

Estrogen is thought to enhance cognitive functions by modulating the production of acetylcholine in basal forebrain neurons; a system that projects to the cerebral cortex and hippocampus and plays a central role in learning and memory. To elucidate the mechanism of estrogen action in the cholinergic system, we utilized a combined in vivo autoradiography/immunocytochemistry technique to evaluate the distribution of estrogen binding sites in cholinergic neurons of the rat basal forebrain. The results of these studies revealed that a portion of the cholinergic neurons in the medial septum (41%), vertical (32%) and horizontal (29%) limbs of the diagonal band and in the substantia innominata/nucleus basalis (4%) contained estrogen receptors. Through the use of a double-label in situ hybridization/immunocytochemistry technique we have shown that estrogen receptor-alpha is the predominant estrogen receptor in the cholinergic neurons, with only a few cells containing estrogen receptor-beta.The results of these studies provide evidence that biologically active estrogen receptors are present in the basal forebrain cholinergic neurons of the adult rat brain, with estrogen receptor-alpha being the predominant receptor subtype. The demonstration that cholinergic neurons contain estrogen receptors is consistent with the possibility that estrogen directly modulates the activity of cholinergic neurons in rats and may provide insight as to how estrogen improves cognitive functions in women.     

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。     

Alpha-adrenergic receptor (alpha(2 A )) is colocalized in basal forebrain cholinergic neurons: a light and electron microscopic double immunolabeling study

A variety of data suggest that noradrenaline and acetylcholine may interact in the basal forebrain, however no morphological studies have addressed whether indeed cholinergic neurons express adrenergic receptors. We have investigated the presence of alpha-adrenergic receptor subtype alpha2A-AR in cholinergic neurons of the basal forebrain. Cholinergic neurons were identified with an antibody against choline acetyltransferase and the receptor with a polyclonal antibody raised against a 47 amino acid fragment of the third intracellular loop of the alpha2A-AR. For double labeling at the light microscopic level the Ni-DAB/DAB technique was used, and for electron microscopy an immunoperoxidase/immunogold method was applied. We detected the alpha2A-AR protein in cholinergic as well as in non-cholinergic neurons. Almost half of all cholinergic neurons contained this adrenergic receptor. Double-labeled neurons were distributed throughout the rostro-caudal extent of the basal forebrain cholinergic continuum, including the medial septum, vertical and horizontal diagonal band nuclei, pallidal regions, substantia innominata and the internal capsule. Non-cholinergic neurons that expressed the alpha2A-AR outnumbered cholinergic/alpha2A-AR neurons by several factors. Electron microscopy confirmed the presence of alpha2A-AR in cholinergic neurons in the medial septum, vertical and horizontal diagonal band nuclei. Gold particles (10 nm) indicative of alpha2A-AR were diffusely distributed in the cytoplasm and accumulated in cytoplasmic areas near the Golgi complex and cysterns of the endoplasmic reticulum and were associated with the cellular membranes at synaptic and non-synaptic locations. Since many of the alpha2A-AR+/non-cholinergic neurons we detected are likely to be GABAergic cells, our data support the hypothesis that noradrenaline may act via basal forebrain cholinergic and non-cholinergic neurons to influence cortical activity.