睫状神经营养因子对严重烫伤大鼠纹状体及海马 NOS 阳性神经元的影响

目的：观察大鼠严重烫伤后纹状体和海马ＮＯＳ阳性神经元数目和阳性反应面积的变化及睫状神经营养因子（ＣＮＴＦ）对其的影响。方法：应用ＮＡＤＰＨ－ｄ酶组织化学的方法。结果：大鼠体表烫伤后３天,纹状体ＮＯＳ阳性神经元数目明显增加,梁色呈强阳性,阳性反应面积增加。海马ＮＯＳ阳性神经元数变化不明显,仅见阳性反应面积增加,睫状神经营养因子可降低纹状体的ＮＯＳ阳性神经元数目、阳性反应面积,ＮＯＳ阳性神经元着色较淡     

血管性痴呆大鼠记忆障碍与海马神经型一氧化氮合酶表达的关系

目的：探讨NO参与血管性痴呆大鼠学习记忆障碍的作用机制。方法：要用4－血管阻断的方法建立大鼠血管性痴呆模型,以免疫组化法检测海马神经型一氧化氮合酶蛋白表达的变化;以Nissl染色方法,结合图象分析统计海马神经元丢失比率,同时采用Y－型迷宫,进行行为学检测,定量测定其学习记忆成绩,结果：在血管性痴呆大鼠空间分辨学习记忆能力发生严重障碍时,海马CA1区神经元丢失比率较正常对照组增高,神经型一氧化氮合酶蛋白表达增加。结论：神经型一氧化氮合酶可能引起海马CA1区神经元凋亡或坏死增加,海马神经元受损,导致血管性痴呆大鼠学习记忆障碍。     

应激性防御反应过程中脑内一氧化氮合酶阳性神经元分布的变化

本实验采用 NADPH-d方法研究发现 :在应激的早期 ( 1～ 6d) ,一氧化氮合酶阳性神经元在大脑皮质、基底前脑、纹状体、间脑和脑干内出现的部位增多 ,一氧化氮合酶阳性神经元的数量也增多 ;而在应激的晚期 ( 9d以后 ) ,一氧化氮合酶阳性神经元出现的部位及数量明显减少。提示在慢性应激的早期一氧化氮合酶活性增高 ,合成一氧化氮的能力增强 ;而在应激的晚期一氧化氮合酶活性降低 ,合成一氧化氮的能力降低     

大鼠纹状体内一氧化氮合酶阳性神经元的发育

用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组化方法观察Ｅ１４ｄ起至生后２８ｄ这段时间大鼠纹状体一氧化氮合酶阳性神经元的发育，结果：胚龄１６ｄ时，尾壳核内已有一氧化氮合酶的表达，此时细胞数量少，细胞圆形，无突起或仅有一短的突起，胚龄１８ｄ一氧化氮合酶阳性神经元的数量增多，生后１display status     

应激性防御反应过程中脑内一氧化氮合酶

本实验采用NADPH-d方法研究发现在应激的早期(1～6d),一氧化氮合酶阳性神经元在大脑皮质、基底前脑、纹状体、间脑和脑干内出现的部位增多,一氧化氮合酶阳性神经元的数量也增多;而在应激的晚期(9d以后),一氧化氮合酶阳性神经元出现的部位及数量明显减少．提示在慢性应激的早期一氧化氮合酶活性增高,合成一氧化氮的能力增强;而在应激的晚期一氧化氮合酶活性降低,合成一氧化氮的能力降低。     

局部皮质内注射海人酸对皮质和海马一氧化氮合酶阳性神经元的影响

本实验用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组织化学方法结合ＧＦＡＰ免疫组化方法，对微量海人酸皮质内注射后的一氧化氮合酶阳性神经元和胶质细胞等的变化进行了研究．结果发现：注射区内的一氧化氮合欧阳性神经元很快消失；注射侧皮质和海马的旧阳性神经元和神经末梢溃变；至注射海人酸后８ｈ，这些变化波及到对侧皮质和海马．随着皮质内一氧化氮合酶阳性神经元的溃变，在注射侧皮质和海马内的一些神经元、星形胶质细胞出现新的一氧化氮合酶活性，这些新的酶活性可能是诱导型的一氧化氮合酶．这些结果表明：表达一氧化氮合酶的皮质和海马神经元对海人酸的毒性很敏感，神经细胞和非神经细胞中出现的诱导型的一氧化氮合酶可能是海人酸引起脑损伤时机体的适应性反应．     

大鼠腰神经根受压后背根神经节及脊髓后角神经元型一氧化氮合酶阳性神经元

目的：探讨大鼠腰神经根受压后后背根神经节和脊髓后角神经元型一氧化氮合酶阳性神经元的变化规律。方法：选用１２只Ｗｉｓｔａｒ大鼠,随机分为实验组和正常组,采用免疫组织化学ＡＢＣ法结合图像分析系统进行研究。结果：大鼠腰神经根受压后４周,实验组背根神经节中神经元型一氧化氮合酶阳性神经元细胞数、平均面积明显增多,脊髓后角神经元型一氧化氮合酶阳性神经末梢也明显增多,与正常组相比均有显著性差异。神经元形态以中、小型细胞为主。结论：大鼠腰神经根受压后感觉神经元神经元型一氧化氮合酶表达上调,提示神经元型一氧化氮合酶可能与根性腰腿痛的发生有关。     

肝性脑病大鼠海马齿状回神经元形态及一氧化氮合酶表达的变化

目的:观察肝性脑病模型组大鼠海马齿状回内神经元的变化及一氧化氮合酶(NOS)的表达,探讨海马神经元的形态学改变及一氧化氮(NO)在肝硬化和肝性脑病发病机制中的作用。方法:先对50只雄性大鼠进行Morris水迷宫测试,之后将动物分为正常对照组和实验模型组。9周后建立CCL4肝性脑病模型,分别取两组大鼠肝、海马组织进行HE染色、Nissl染色及NADPH-d染色。结果:(1)肉眼下可见模型组肝脏普遍呈坏死性肝硬化;(2)HE模型组血氨浓度明显高于正常对照组(P<0.05);(3)Nissl染色结果显示实验组大鼠海马神经元数目减少、染色较浅,胞浆内Nissl体减少或消失;(4)NADPH-d染色结果显示实验组可见粗大轴突着色,树突联系广泛;对照组则少有粗大轴突着色,树突间联系不如实验组广泛。实验组一氧化氮合酶(NOS)阳性神经元染色较对照组深,为紫蓝或深蓝色,且阳性神经元的数目较多。结论:(1)血氨增高是肝性脑病发病机制之一;(2)肝性脑病时海马受到损伤,并且一氧化氮(NO)可能介导了神经元的损伤。     

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分布变化

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，长度增加，多极细胞占64％;28d后一氧化氮合酶阳性神经元胞体面积，树突分枝长度明显减小，分枝简单化;35d后接近成年动物水平（120d）.生后7d时，一氧化氛合酶阳性神经元主要位于视区的白质和皮层的5、6层中，7d后该神经元及神经纤维在第2／3及4层中明显增多，这种分布状态在35d后趋于稳定。上丘表层中的一氧化氮合酶阳性细胞在生后第2周逐渐出现，第3周迅速增加，第4周达最大值，以后下降并趋于稳定水平。结果提示：大鼠生后发育过程中视觉中枢的一氧化氮合酶阳性神经元数量及形态变化与视觉发育的可塑性有关。     

大鼠海马和颞叶一氧化氮合酶阳性神经元在学习记忆时的表达

目的　对获得空间辨别性学习记忆大鼠的海马结构和颞叶皮质内一氧化氮合酶 (NOS)免疫阳性神经元系统的观察 ,为一氧化氮 (NO)在学习记忆活动中的作用提供形态学依据。方法　以经水迷宫训练获得空间辨别性学习记忆的大鼠为模型组 ,建立游水对照组和空白对照组。用免疫组化的方法观察 3组大鼠海马和颞叶的NOS阳性神经元的形态学特征及测定免疫反应阳性产物的光密度值 (OD )。结果　 (1)NOS阳性神经元在 3组大鼠海马和颞叶呈散在分布。在海马CA1、CA2、CA3、CA4及龄状回 (DG)都有少量分布 ,颞叶以Ⅱ、Ⅲ、Ⅴ、Ⅵ层分布为主。神经元胞体形态有锥体形 ,圆形或椭圆形 ,梭形3种。 (2 )模型组大鼠海马和颞叶皮质NOS阳性神经元较对照组明显增多。 (3)其免疫反应阳性产物的OD值也较对照组明显增大。结论　NOS阳性神经元形态发生了可塑性变化 ,参与了学习记忆     

Selective neuronal death after transient forebrain ischemia in the Mongolian gerbil: a silver impregnation study

An important feature of ischemic brain damage is the exceptional vulnerability of specific neuronal populations and the relative resistance of others. Silver impregnation was used to delineate the extent and time-course of neuronal degeneration produced by 5 min of complete forebrain ischemia in the Mongolian gerbil. Lesions were confined to four brain regions: (1) hippocampal areas CA1, CA2-CA3a and CA4; (2) the dorsomedial portion of the lateral septal nucleus; (3) the dorsolateral portion of the striatum; and (4) the somatosensory neocortex. The ischemic lesion evolved with time in all four regions, but at different rates. Somatic argyrophilia developed rapidly in the striatum and hippocampal area CA4 (maximal in 24 h or less), at intermediate rates in the somatosensory neocortex, hippocampal areas CA1a and CA2-CA3a and the lateral septal nucleus (maximal in 2 days), and slowly in hippocampal area CA1b (maximal in 3 days). These results emphasize that the extent and rate of neuronal degeneration can vary even within a presumably homogeneous neuronal population, as evidenced by the different results in areas CA1a and CA1b. Similar results were obtained from analysis of brain sections stained with Cresyl Violet, hematoxylin-eosin or hematoxylin-eosin/Luxol Fast Blue. Terminal-like silver granules were observed in the projection fields of degenerated neurons. They also appeared, however, in the perforant path terminal zone of the hippocampal dentate molecular layer 1-2 days after transient ischemia and in stratum oriens and stratum radiatum of area CA1b prior to somatic degeneration. These granular deposits could not be clearly related to the degeneration of neuronal somata. Novel findings of this study include the degeneration of some dentate basket cells and lateral septal neurons and the appearance of terminal-like argyrophilia in the hippocampal formation without any obvious relation to somatic degeneration. Some of our results lend support to the hypothesis that ischemic neuronal cell death constitutes an excitotoxic process. Other results, however, suggest that the selective vulnerability of neurons to transient ischemia must involve factors beyond excitotoxicity.     

NGF在成年猴脑的分布

为了解NGF在成年猴脑的分布,采用免疫组化SP法对成年猴脑多个冠状位切片进行免疫组化反应。结果证明,NGF阳性反应神经元主要分布于大脑皮质Ⅲ、V层,小脑Purkinje细胞,海马,齿状回,纹状体,脑干网状结构等处。此外,在黑质、舌下神经核、迷走神经背核、前庭神经核、三叉神经核、疑核、下橄榄核也出现NGF阳性反应。在大脑和脑干还观察到NGF阳性胶质细胞。本实验结果表明,在成年猴脑的多个脑区有NGF表达,提示NGF可能涉及猴脑某些神经元及胶质细胞的生理过程。     

Dexamethasone induces limited apoptosis and extensive sublethal damage to specific subregions of the striatum and hippocampus: implications for mood disorders

It has been shown previously that the synthetic corticosteroid dexamethasone induces apoptosis of granule cells in the dentate gyrus and striatopallidal neurons in the dorsomedial caudate-putamen. We investigated whether or not dexamethasone can induce damage to other neuronal populations. This issue was addressed using OX42 immunohistochemistry to visualise activated microglia and thereby gauge the extent of dexamethasone-induced neuronal death. A single dose of dexamethasone (20mg/kg, i.p.) administered to young male Sprague-Dawley rats induced a strong microglial reaction which was restricted to the striatum, the dentate gyrus and all of the CA subfields of the hippocampus. Some OX42-immunoreactive cells were also seen in the lateral septal nucleus. Subsequent quantitative analysis of silver/methenamine-stained sections confirmed that acute administration of dexamethasone induced apoptosis in the striatum and all regions of the hippocampus at doses as low as 0.7mg/kg. In contrast, dexamethasone failed to induce apoptosis in the lateral septal nucleus at doses up to 20mg/kg. The levels of dexamethasone-induced striatal and hippocampal apoptosis were attenuated by pretreatment with the corticosteroid receptor antagonist RU38486 (Mifepristone), which implies that the cell death was mediated by a corticosteroid receptor-dependent process. We further determined whether dexamethasone induced sublethal damage to neurons by quantifying reductions in the number of microtubule-associated protein-2-immunoreactive striatal and hippocampal cells following injection of the corticosteroid. Dexamethasone induced dramatic decreases in the striatum, with the dorsomedial caudate-putamen being particularly affected. Similar damage was seen in the hippocampus, with the dentate gyrus and CA1 and CA3 subfields being particularly vulnerable.Equivalent corticosteroid-induced neuronal damage may occur in mood disorders, where the levels of endogenous corticosteroids are often raised. Corticosteroid-induced damage of striatal and hippocampal neurons may also account for some of the cognitive deficits seen following administration of the drugs to healthy volunteers.     

A 72 kDa heat shock protein is protective against the selective vulnerability of CA1 neurons and is essential for the tolerance exhibited by CA3 neurons in the hippocampus

The correlation between the expression of a 72 kDa heat shock protein and vulnerability of hippocampal CA1, CA3, and dentate gyrus regions to glutamate toxicity was investigated using a highly specific antisense oligonucleotide technique. Glutamate (1 mM, 15 min) caused region-dependent neuronal damage in cultured hippocampal slices 24 h after exposure and the most severe damage was observed in CA1. When slices were heat-shocked (43.5 degrees C, 30 min) before exposure to glutamate, neuronal damage in CA1 was attenuated. The strongest protection was observed when the interval between the heat shock and the exposure to glutamate was 3 days, which coincided with the maximal induction of a 72 kDa heat shock protein in neurons. When the expression of a 72 kDa heat shock protein was suppressed by the antisense oligonucleotide, the protective effect of the heat shock was completely inhibited. Glutamate itself also induced a 72 kDa heat shock protein in neurons, region-dependently, 24 h after the exposure. The signal of a 72 kDa heat shock protein in CA3 and dentate gyrus was significantly stronger than that in CA1. When the antisense oligonucleotide was applied, the damage in CA3 and dentate gyrus was exaggerated dose-dependently, and this effect was more remarkable in CA3 than in the dentate gyrus. Based on these data, we concluded that: (i) a 72 kDa heat shock protein has a protective effect against the selective vulnerability of CA1 neurons, (ii) a 72 kDa heat shock protein is an essential factor for the tolerance exhibited by CA3 neurons, and (iii) dentate gyrus tolerance is based on mechanisms other than those mediated through a 72 kDa heat shock protein.     

17 Beta-oestradiol attenuates dexamethasone-induced lethal and sublethal neuronal damage in the striatum and hippocampus

Abnormal corticosteroid release is extensively associated with mood disorders. This association may result from the toxic actions of endogenous corticosteroids which can induce apoptosis of hippocampal neurons. Similarly, dexamethasone, a synthetic corticosteroid, can induce lethal and sublethal damage to rat hippocampal and striatal neurons and can result in steroid-induced psychoses in humans. The experiments reported here tested the hypothesis that pre-treatment with oestrogen would also attenuate dexamethasone-induced neuronal damage as oestrogens have neuroprotective actions against a variety of insults and falling levels of oestrogen are associated with increased vulnerability to mood disorders. Male Sprague-Dawley rats received three systemic injections which were a combination of vehicle, 17-beta-oestradiol (0.2 mg/kg, s.c.), the oestrogen receptor antagonist tamoxifen (10 mg/kg, s.c.) and dexamethasone (0.7 mg/kg, i.p.) and were killed 24 h after the final injection. Injections of dexamethasone (when preceded by vehicle injections) resulted in elevated levels of apoptosis and sub-lethal damage, as demonstrated by reduced levels of microtubule-associated protein-2-immunopositive neurons, in the striatum and hippocampus. This damage was regional with the dorsomedial caudate putamen and the dentate gyrus and CA1 and CA3 hippocampal sub-fields being particularly affected. Pretreatment with oestrogen substantially attenuated the dexamethasone-induced neuronal damage. This oestrogen-induced neuronal protection was in turn virtually eliminated by giving an initial injection of tamoxifen. These results suggest, therefore, that oestrogens can protect from corticosteroid-induced neuronal damage via an oestrogen receptor-mediated process.     

大鼠下丘脑一氧化氮合酶（NOS）阳性神经元的分布

观察大鼠下丘脑各核团NOS阳性神经元的分布。采用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶（NADPH－d）法，结果显示，大量NOS阳性神经元见于下丘脑外侧区、视上核（SO）和室旁核（Pa）；出现较多NOS阳性神经元的部位是视前大细胞核，见到少量NOS阳性神经元的部位是室周核、视前内侧区、视前外侧区和下丘脑前区。结论：NOS阳性神经元分布于下丘脑的许多核团。     

听源性惊厥点燃后听觉核团和前脑结构内一氧化氮合酶阳性神经元的形态学观察

为探讨一氧化氮在听源性惊厥点燃中的作用．用NADPH-d组织比学方法和体视学分析,研究厂Wistar种系的听源性惊厥易感大鼠（P77PMC）惊厥和点燃后听觉核团内NOS阳性神经元的分布及差异。结果显示：（1）P77PMC大鼠一次惊厥后,听觉核团和前脑结构内可见广泛的NOS阳性神经元,其分布类似于正常大鼠;（2）点燃后,听觉核团和前脑结构内NOS染色增深,NOS阳性神经元增加。特别是在下丘和嗅周皮质．除NOS阳性神经元明显增多外．其分布亦发生改变。本研究提示,听源性惊厥可诱导NOS表达增加,这种增加可能对于保持神经元增高的易感性有关。     

大鼠下丘脑室旁核中一氧化氮合酶阳性神经元的生后发育

本文用NADPH－d组织化学方法观察NOS阳性神经元在大鼠下丘脑室旁核生后发育各阶段（1、7、14、21、28和90d）的形态及分布特征。结果显示，1d时下丘脑室旁核内已有密集的NOS阳性神经元分布，但随生长发育，室旁核的截面积逐渐变大，其中的NOS神经元主要集中在该核的外侧大细胞部以及腹侧部，单位面积中的NOS神经元的密度逐渐降低。到21d，下丘脑室旁核NOS阳性神经元的分布密度较1d时下降50％。28d以后至成年鼠（90d），此密度维持在一定水平．提示下丘脑室旁核中NOS神经元的生后发育主要在生后1d至21d之间，并提示胚胎时期该核中已有NOS神经元存在。     

听源性惊厥易感大鼠惊厥和点燃后前脑结构内的c—fos表达

为探讨听源性惊厥点燃和前脑结构的关系，用免疫细胞化学方法结合体视学分析，研究Ｗｉｓｔａｒ种系的听源性惊厥易感大鼠惊厥和点燃后，前脑结构内ｃ－ｆｏｓ表达的差异。结果显示，１．正常Ｗｉｓｔａｒ大鼠接受一次强音刺激后，海马，齿状回，杏仁核，内嗅皮质，嗅周皮质和额－顶皮质内未见Ｆｏｘ阳性神经元；２．Ｐ７７ＰＭＣ大鼠一次惊厥后，除海马，齿状回外，上述被检各区内可见广泛的Ｆｏｓ阳性神经元，其分布具有区域差异．     

C57black/6小鼠全脑缺血模型的海马区Bcl-2和Bax的表达

使用 C5 7black/6小鼠制造的全脑缺血模型 ,观察全脑缺血后海马 Bcl-2和 Bax的表达 ,为这种新的模型在脑缺血研究中的应用提供实验依据。双侧颈总动脉夹闭 15 min诱发全脑缺血模型 ,2 4h后取脑组织进行 Bcl-2和 Bax免疫组织化学染色。缺血组海马 Bax阳性反应神经元数目增多 ,主要分布在 CA1 区 ,胞浆深染 ,假手术组 Bax阳性细胞数目少 ,染色浅。缺血组 CA3区和齿状回 Bcl-2阳性反应神经元数目增多 ,胞浆染色深 ,假手术组 Bcl-2阳性细胞数目少 ,染色浅。C5 7black/6小鼠全脑缺血模型的海马内 Bcl-2和 Bax表达发生改变 ,Bax表达增加在 CA1 区 ,Bcl-2表达增加在 CA3区和齿状回 ,提示二者在该模型的脑缺血后神经细胞死亡过程中发挥作用