神经生长因子促进老年痴呆鼠学习记忆恢复和海马突触重建

切断老年鼠（２４月龄）左侧穹窿海马伞（ＦＦ），造成隔－海马胆碱能系统损伤的痴呆模型。用Ｍｏｒｒｉｓ水迷宫和体视学分析ＮＧＦ对模型鼠学习记忆和突触的影响。实验１个月后显示：（１）定位航行试验中，损伤组大鼠寻找平台的潜伏期，稳定后的平均值为４０ｓｅｃ，而ＮＧＦ治疗组为２２ｓｅｃ，相互间具有显著性差异（Ｐ＜０．０５）；（２）空间搜索试验中，损伤组在原平台象限跨越相应平台位置次数为１．９次，ＮＧＦ治疗组为５．９次，两者间有统计学意义（Ｐ＜０．０１）；（３）损伤组损伤侧齿状回分子层突触数密度和面密度分别下降２９％和１９．０３％，平均面积增大１１．４％。ＮＧＦ治疗组，突触数密度和面密度与损伤组相比，有显著升高（Ｐ＜０．０５），而平均面积显著下降（Ｐ＜０．０５），都接近于正常组；（４）损伤组损伤侧齿状回分子层突触前终末内线粒体的体密度和数密度分别下降３０．７％和５６．５％，体积增大３７．０９％。ＮＧＦ治疗组的体密度、数密度和体积与正常组相比，差异无显著性（Ｐ＞０．０５）。提示ＮＧＦ能够改善老年痴呆模型鼠学习记忆能力和促进海马突触重建。     

CCl_4 所致大鼠肝损伤自愈过程中颌下腺颗粒曲管细胞表皮生长因子的免疫组织化学研究

为探讨肝损伤后颌下腺颗粒曲管（ｇｒａｎｕｌａｒｃｏｎｖｏｌｕｔｅｄｔｕｂｕｌｅ，ＧＣＴ）细胞内表皮生长因子（ｅｐｉｄｅｒｍａｌｇｒｏｗｔｈｆａｃｔｏｒ，ＥＧＦ）的变化与肝的自愈过程之间的关系，本研究用免疫组织化学方法观察了ＣＣｌ４所致大鼠肝损伤自愈过程中颌下腺颗粒曲管细胞内表皮生长因子的反应强度及相关数量变化。结果显示：肝损伤后的第２、４、８ｄ，ＥＧＦ阳性细胞数增加（Ｐ＜０．０５，Ｐ＜０．０１，Ｐ＜０．０１）。肝损伤第２ｄ，ＧＣＴ细胞内弱阳性细胞数增多（Ｐ＜０．０１），第４ｄ，中等及弱阳性细胞数增多（Ｐ＜０．００１，Ｐ＜０．００１），至第８ｄ，强、中、弱阳性细胞数均增多（Ｐ＜０．００１，Ｐ＜０．００１，Ｐ＜０．０５）。结果表明：颌下腺ＧＣＴ细胞内的ＥＧＦ参与肝损伤后的修复及再生。     

表皮生长因子对大鼠血淋巴细胞c—fos基因表达的效应

本研究的目的是探讨表皮生长因子对大鼠血淋巴细胞转化率和ｃ－ｆｏｓ基因表达的效应。结果表明：大鼠血淋巴细胞呈免疫反应性，胞质内可见到ＥＧＦｍＲＮＡ信号；ＥＧＦ瓣育可显著提高大鼠血淋巴细胞的转化率和ｃ－ｆｏｓ基因表达水平，与对照组相比较，Ｐ＜０．００１，而与植物血凝素孵育组无显著性差异，Ｐ＞０．０５。     

"缺血"对大鼠大脑皮层神经元NMDA受体通道的影响

目的：研究“缺血”大鼠大脑大皮层神经元Ｎ－甲基－Ｄ－天冬氨酸（ＮＭＤＡ）受体通道的单通道变化特征。方法：细胞贴附式膜片钳技术。结果：在“缺血”状态下，ＮＭＤＡ受体通道３５ｐＳ和１００ｐＳ电导水平的开放概率分别由对照组的０．０７９±０．００６和０．０６７±０．００４增加到０．３０８±０．１５５和０．４８８±０．１２６（Ｐ＜０．０１），３５ｐＳ通道开放时间常数τ２由对照值（４．１７±０．３８）ｍｓ增加到（８．５４±２．０５）ｍｓ（Ｐ＜０．０１），关闭时间由（７５．５０±１４．１０）ｍｓ缩短到（１１．８０±４．３０）ｍｓ（Ｐ＜０．０１）。结论：“缺血”可显著开放大鼠大脑皮层神经元ＮＭＤＡ受体通道，使钙内流增加，对胞内钙超载起重要作用，此可能是脑缺血细胞损伤的机制之一。     

双侧眼球摘除对大鼠视交叉上核的影响──免疫组化及光电镜体视学研究

采用双侧眼球摘除大鼠模型，术后存活不同时间，用免疫组化法探讨视交叉上核内ＶＩＰ和ＡＶＰ免疫反应强度和面积的变化；对变化明显的２１ｄ组进一步用光镜和电镜体现学方法进行形态学研究。＜１＞免疫组化研究：ＶＩＤ免疫染色，２１ｄ组免疫反应强度和面积均比对照组降低（Ｐ＜０．０５），２ｄ和７ｄ组免疫反应强度和面积与对照组相比无显著差异。ＡＶＰ免疫染色，三个时间实验组免疫反应强度和面积均与对照组无明显差异。＜２＞体视学研究：实验组ＶＩＰ样神经元胞体体积、胞核体积、核仁平均直径均明显缩小，粗面内质网和高尔基复合体表面积密度明显下降。以上所见提示摘除眼球２ｌｄ时，视交叉上核内直接接受光信息的ＶＩＰ样神经元的免疫活性下降是因阻断光传入所造成的。光传入的阻断和视神经纤维的溃变使视交叉上核中ＶＩＰ样神经元的结构呈现功能性改变，推测这些变化将引起该神经元肽类物质含量的下降。     

大鼠视觉中枢生后发育过程中的一氧化氮合酶阳性神经元的形态及 …

本文用ＮＡＤＰＨ－黄递酶组织化学技术研究了生后不同年龄段（０、７、１４、２１、２８、３５、６０、１２０ｄ）Ｗｉｓｔａｒ大鼠视皮层（１７区）和上丘表层中一氧化氮合酶阳性神经元的形态及分布的变化。结果表明：视皮层１７区中的一氧化氮合酶阳性神经元在生后７ｄ时开始出现，但胞体小，树突分枝少而短，以双极细胞为主，占６８．０％；１４ｄ时数量达到高峰；且１４￣２１ｄ中，该神经元胞体截面积明显增大，树突分枝复杂化     

bFGF对左旋硝基精氨酸诱导大鼠高血压的影响

本文观察了ｂＦＧＦ对Ｌ－ＮＮＡ诱导的大鼠高血压形成的影响及其机制。结果发现：（１）ｂＦＧＦ使高血压大鼠的平均动脉压较单纯高血压动物的血压降低３．８ｋＰａ（ｐ＜０。０５）;主动脉对乙酰胆碱（ＡＣｈ）的最大舒张反应增加６４．２％（Ｐ＜０．０１）：（２）注射ｂＦＧＦ使高血压大鼠血浆及主动脉薄片孵育液中的亚硝酸盐（ＮＯ２－）含量均显著增高,并明显恢复了血管薄片对ＡＣｈ刺激的敏感性;（３）ＭＧＦ使高血压大鼠血管壁的ｔＮＯＳ、ｉＮＯＳ及ｃＮＯＳ含量分别较单纯高血压大鼠的增加２５．５％、１５．６％和４５．７％（Ｐ＜０．０５或Ｐ＜０．０１）。结果提示：ｂＦＧＦ具有明显的拮抗Ｌ－ＮＮＡ诱导的高血压形成的作用,其机理与刺激血管壁ＮＯＳ活性、增加ＮＯ的产生有关。     

白细胞介素-2对大鼠海马脑电图和胶质细胞的影响——免疫组织化学和显微图像分析等方法的研究

为探讨白细胞介素与癫痫发病机理的关系，该研究应用脑电图仪记录了侧脑室内注射白细胞介素－２（ＩＬ－２）后，大鼠海马脑电图的变化。结果显示：侧脑室内注射ＩＬ－２后，大鼠海马脑电图出现阵发性痫性放电，表现为频发棘波；应用免疫组织化学方法（ＰＡＰ法）和显微图像分析技术，观察到：侧脑室内注射ＩＬ－２后，大鼠海马回和齿状回内胶质原纤维酸性蛋白（ＧＦＡＰ）免疫反应的胶质细胞的数量明显增多、胞体截面积增大、突起及其分支增多。对大鼠海马回ＣＡ１区ＧＦＡＰ免疫反应的胶质细胞进行显微图像分析，结果显示；与正常对照组相比，ＩＬ－２组的细胞数量约增加０．４８倍、胞体截面积约增加１．７３倍、周长约增加１．０９倍、平均光密度约增加０．２０倍、积分光密度约增加２．３１倍。统计结果表明：差异有极显著性意义（Ｐ＜０．０１）。上述结果提示：大鼠侧脑室内注射ＩＬ－２可促进海马星形胶质细胞的增殖、肥大和细胞突起的萌芽。     

纹状体提取液增强体外培养的中脑黑质神经元的发育

制备新生２ｄ龄大鼠纹状体提取液及其不同分子量的组分，用快速自动化色微量分析法检测它们对体外培养的１４ｄ齿大鼠胚胎中脑黑质神经元的影响，结果表明，纹，状体提取液有支持中脑黑质神经元生存及增强其活性的作用，而且具有剂量依赖关系，其最适浓度为１．２５μｇ／ｍｌ。纹状体提取液还能促进中脑黑质神经元对＾３Ｈ－ＤＡ和＾３Ｈ－ＧＡＢＡ的摄取，同对照组相比，有显著性差异（Ｐ＜０．０１）。通过检测纹状体提取液小于１     

老年性记忆减退大鼠内侧隔核-斜角带神经生长因子受体阳性神经元的改变

为探讨神经生长因子受体在老年性记忆减退大鼠记忆相关区域表达的改变,选用雄性ＳＤ 大鼠（青年组２０ 只,老年组４０ 只）进行Ｍｏｒｒｉｓ水迷宫行为学测定,老年组又分为老年记忆减退组（简称老年减退组）和老年记忆正常组（简称老年正常组）。分析内侧隔核－斜角带中神经生长因子受体表达的改变。老年减退鼠内侧隔核、斜角带垂直支和斜角带水平支三个核团神经生长因子受体阳性神经元的数量较老年正常组分别下降了３７．８９％ 、３９．７５％ 和３８．８６％ （Ｐ＜ ０．０１）。受试大鼠逃避潜伏期与内侧隔核－斜角带的神经生长因子受体阳性神经元数量呈负相关（内侧隔核ｒ＝ －０．８２３８,Ｐ＜ ０．０１;斜角带垂直支ｒ＝ －０．９０７６,Ｐ＜ ０．０１;斜角带水平支ｒ＝ －０．８１３８,Ｐ＜ ０．０１）。老年减退组神经生长因子受体阳性神经元灰度值较老年正常组三个核团分别下降３０．９１％ 、２９．６７％ 和３６．７１％ （Ｐ＜ ０．０１）,胞体面积较老年正常组减少２９．０５％ 、１７．５２％ 和３７．８７％ （Ｐ＜ ０．０１）。老年减退组神经生长因子受体的丢失可能是引起老年性记忆减退的机制之一。     

Nerve-growth-factor-dependent and cell-density-independent survival of septal cholinergic neurons in culture from postnatal rats

We have established a primary neuronal cell culture technique from the postnatal (P11 to P15) rat CNS to study the nerve growth factor (NGF) response to basal forebrain cholinergic neurons. The survival of septal cholinergic neurons in culture was monitored both by the determination of choline acetyltransferase activity and by counting acetylcholinesterase-positive cells. Cells obtained from postnatal septal regions were found to require a plentiful oxygen supply during the dissociation of the cells. NGF-mediated survival of the septal cholinergic neurons was similarly observed in the cultures by using different plating cell densities up to 12.5 X 10(5) cells/cm2. These results suggest that the promotion by NGF of cell survival in culture is independent of plating cell density.     

Basic fibroblast growth factor suppressed the enhancement of choline acetyltransferase activity induced by nerve growth factor

We investigated change of choline acetyltransferase (ChAT) activities in rat embryonic (16 days) septal neuron culture in treatment with basic fibroblast growth factor (bFGF) and nerve growth factor (NGF). Total ChAT activity increased by addition of bFGF, NGF, and bFGF plus NGF with dose-dependent manner. NGF showed much enhancement of specific ChAT activities per mg protein, but bFGF or bFGF plus NGF, respectively showed little or slightly enhanced ChAT activities. In histochemical studies with anti-ChAT antibody staining, cholinergic neurons in NGF-treated culture were stained more strongly than those in other conditioned cultures such as control, bFGF-treated, and bFGF plus NGF-treated cultures. These results suggest that bFGF enhances total ChAT activity but not cellular ChAT activity and further suppresses the enhancement of cellular ChAT activity induced by NGF in septal neuron culture.     

Septal cholinergic neurons from postnatal rat can survive in the dissociate culture conditions in the presence of nerve growth factor

The survival effect by nerve growth factor (NGF) on the cholinergic neurons of postnatal rat septal neurons in culture was examined. When the septal neurons from 10 to 12-day-old rats were cultured without NGF, the activities of choline acetyltransferase gradually decreased during the period of cultivation. The addition of NGF to the culture prevented the decline of activities. And, the number of acetylcholinesterase-positive neurons in culture with NGF was found to be more than that without NGF, after 5 days in culture. These results suggest that NGF promotes the survival of septal cholinergic neurons from postnatal rats in culture.     

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     

Denervation of dopaminergic neurons with 6-hydroxydopamine increases nerve growth factor content in rat brain.

Denervation of dopaminergic neurons by intra nigral injection of 6-hydroxydopamine (6-OHDA) increased nerve growth factor (NGF) content in the cortex and hippocampus, both of which are innervated by cholinergic neurons. The increase continued during an observation period of 0.5-28 days after the lesion. The time course of changes in NGF content was quite different from that of cholinergic neuron denervation. The decreased dopamine content produced in the striatum by 6-OHDA injection was not recovered during the observation period. These results suggest that dopaminergic neuron damage may affect NGF synthesis.     

Schwann细胞促进共培养和共移植的胆碱能神经元的存活和生长

移植神经细胞的低存活率是目前制约脑内移植临床应用的主要因素。本研究采用胚胎大鼠隔核神经元和新生大鼠Schwann细胞的联合培养和联合移植技术 ,分析了 Schwann细胞促进胆碱能神经元存活和生长的可能性。结果显示 ,胆碱能神经元的存活及其突起生长与共培养或共移植 Schwann细胞的存在与多少明显相关。分别与密度为 6× 10 3 /cm2、1.8× 10 4/cm2、5 .4× 10 4/cm2 (密度比为 1∶ 3∶ 9)的 Schwann细胞联合培养 ,存活的乙酰胆碱酯酶阳性细胞数之比为 1∶ 2 .3∶ 3.9;阳性细胞的突起总长度分别为 2 81、42 8和 6 40μm。在与 Schwann细胞混合移植的胚胎隔核细胞中存活的乙酰胆碱酯酶阳性细胞是单独移植的 2 .2倍 ,共移植的阳性细胞也有较密集的突起生长。结果提示 ,共培养和共移植 Schwann细胞能显著提高胆碱能神经元的存活能力 ,促进其生长     

神经生长因子在人胚胎神经管发育的定位表达

目的研究神经生长因子(NGF)在人胚胎神经管发育过程中的定位表达。方法用胚胎龄为30天的人胚胎行免疫细胞化学ABC法染色。结果在人胚胎神经管室带,神经元的细胞浆和细胞核NGF免疫反应阳性;在中间带一部分神经元的胞核NGF免疫反应阳性,另外一部分神经元的胞核NGF免疫反应阴性,神经元的突起NGF免疫反应阳性;在边缘带NGF的表达与中间带相似。神经管的吻侧NGF、蛋白表达较强,神经管的尾侧NGF蛋白表达较弱。中胚层体节之间可见NGF免疫反应阳性的细胞。结论NGF是神经管诱导分化的重要信号分子,它通过神经管中间带的NGF水平信号和神经管与中胚层相互作用的垂直信号诱导神经管的发育分化,在神经管的发育中具有十分重要的作用。     

Nerve growth factor increases choline acetyltransferase but not survival or fiber outgrowth of cultured fetal septal cholinergic neurons

Neurons dissociated from the septal area of fetal rat brains were grown in culture. Cholinergic neurons were identified by immunocytochemical visualization of choline acetyltransferase and cytochemical demonstration of acetyl cholinesterase. Choline acetyltransferase immunocytochemistry stained cell bodies and proximal processes while acetylcholinesterase cytochemistry visualized the entire neuron. Choline acetyltransferase-positive neurons could only be identified in cultures grown under conditions that produced the maximal choline acetyltransferase activity, measured biochemically. All of the choline acetyltransferase-positive neurons were double stained for acetylcholinesterase while only 6% of the acetylcholinesterase-positive cells were choline acetyltransferase negative in these cultures. These results indicate that acetylcholinesterase is a reliable marker for cholinergic cells in cultures of dissociated septal neurons. Being the more sensitive method, acetylcholinesterase staining was therefore used to identify cholinergic cells in cultures with choline acetyltransferase levels insufficient for immunocytochemical visualization of this enzyme. Addition of nerve growth factor or antibodies to nerve growth factor to the medium did not affect the number of cholinergic neurons surviving in culture. Furthermore, nerve growth factor and anti-nerve growth factor failed to influence the general morphological appearance and the number of processes of these neurons. However, nerve growth factor elevated the biochemically measured activity of choline acetyltransferase up to two-fold. The nerve growth factor-mediated increase in choline acetyltransferase activity was dose dependent with an ED50 of 10 ng/ml (4 X 10(-10) M). The increase was highly specific for nerve growth factor. It was blocked by anti-nerve growth factor, and epidermal growth factor, insulin and other control proteins failed to exert a similar effect. Nerve growth factor had to be present for at least 3 days in the culture medium to increase choline acetyltransferase activity, suggesting that the increase was due to an elevated choline acetyltransferase synthesis rather than to an activation of the enzyme.     

Intraventricular nerve growth factor administration prevents lesion-induced loss of septal cholinergic neurons in aging rats

In young adult rats transection of the fimbria results in loss of cholinergic cell bodies in the septum and this lesion-induced loss is prevented by intraventricular administration of NGF. The present study examined whether NGF administration is equally effective in aging animals. Eighteen-month-old rats received fimbrial transections and were given intraventricular injections of NGF during four weeks. Septal cholinergic neurons were then visualized using NGF receptor immunohistochemistry, which represents a reliable marker for cholinergic neurons in the septal area. The fimbrial transections reduced the number of septal NGF receptor-positive cells to a similar extent as in young animals. NGF treatment of aging rats protected these cells as effectively as in young adult rats.     

The alpha7 nicotinic receptor agonist 4OH-GTS-21 protects axotomized septohippocampal cholinergic neurons in wild type but not amyloid-overexpressing transgenic mice

While activation of alpha7 nicotinic receptors protects neurons from a variety of apoptotic insults in vitro, little is known about this neuroprotective action in vivo, especially under amyloidogenic conditions that mimic Alzheimer's disease. We therefore investigated the effects of 4OH-GTS-21, a selective partial agonist for these receptors, on septohippocampal cholinergic and GABAergic neuron survival following fimbria fornix (FFX) lesions in three strains of mice: C57BL/6J wild type mice; human presenilin-1 mutant M146L (PS1) transgenic mice; and mice expressing both mutant PS1 and Swedish mutant K670N/M671L amyloid precursor protein (APP). Initial studies to demonstrated that 4OH-GTS-21 is likely brain permeant based on its ability to improve passive avoidance and Morris water task behaviors in nucleus basalis-lesioned rats. In FFX-lesioned mice, twice per day i.p. injections of 1 mg/kg of 4OH-GTS-21 for 2 weeks promoted the survival and prevented the atrophy of septal cholinergic neurons. Septal parvalbumin-staining GABAergic neurons were not protected by this treatment, although they also express alpha7 nicotinic receptors, suggesting an indirect, nerve growth factor (NGF)-mediated mechanism. No protection of cholinergic neurons was observed in similarly treated PS1 or APP/PS1 transgenic mice. 4OH-GTS-21 treatment actually reduced cholinergic neuronal size in APP/PS1 mice. Hippocampal amyloid deposition was not affected by FFX lesions or treatment with this alpha7 nicotinic receptor agonist in APP/PS1 mice under these conditions. These results indicate that brain alpha7 nicotinic receptors are potential targets for protecting at-risk brain neurons in Alzheimer's disease, perhaps via their effects on NGF receptors; however, this protection may be sensitive under some conditions to environmental factors such as inhibitory amyloid-peptides.