共查询到20条相似文献，搜索用时 15 毫秒
1.
Nerve growth factor treatment after brain injury prevents neuronal death 总被引：47，自引：0，他引：47
L F Kromer 《Science (New York, N.Y.)》1987,235(4785):214-216
Cholinergic neuronal degeneration after axotomy has been proposed to be due to the loss of a retrogradely transported neurotrophic factor, possibly nerve growth factor (NGF). To test this hypothesis, NGF was continuously infused into the lateral ventricles of adult rats that had received bilateral lesions of all cholinergic axons projecting from the medial septum to the dorsal hippocampus. After 2 weeks of NGF treatment, identification of cholinergic neurons by the presence of the biosynthetic enzyme choline acetyltransferase revealed a dramatic increase (350%) in the survival of the axotomized septal cholinergic neurons. Thus, NGF or an NGF-like molecule can act as a neurotrophic factor for these neurons. 相似文献
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Nerve growth factor gene expression in the developing rat brain 总被引：31，自引：0，他引：31
T H Large S C Bodary D O Clegg G Weskamp U Otten L F Reichardt 《Science (New York, N.Y.)》1986,234(4774):352-355
The regulation of nerve growth factor (NGF) protein and NGF messenger RNA (mRNA) in the developing rat brain has been studied to assess the hypothesis that NGF supports the differentiation of cholinergic neurons in the basal forebrain. In the adult, the major targets of these neurons, the hippocampus and neocortex, contain the highest concentrations of NGF mRNA, but comparatively low ratios of NGF protein to its mRNA. In contrast, a high concentration of NGF protein and a low concentration of NGF mRNA were seen in the basal forebrain, consistent with retrograde transport of NGF protein into this region from the neocortex and hippocampus. In these two target regions NGF and NGF mRNA were barely detectable at birth, their concentrations increased to a peak at day 21, and then NGF mRNA, but not NGF protein, declined threefold by day 35. NGF accumulation in the basal forebrain paralleled that in the target regions and preceded an increase in choline acetyltransferase, suggesting that the differentiation of cholinergic projection neurons is indeed regulated by retrogradely transported NGF. In addition, high ratios of NGF protein to NGF mRNA, comparable to that in the basal forebrain, were seen in the olfactory bulb and cerebellum, suggesting that NGF may be transported into these regions by unidentified neurons. 相似文献
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Expression of beta-nerve growth factor receptor mRNA in Sertoli cells downregulated by testosterone 总被引：4，自引：0，他引：4
H Persson C Ayer-Le Lievre O S?der M J Villar M Metsis L Olson M Ritzen T H?kfelt 《Science (New York, N.Y.)》1990,247(4943):704-707
Nerve growth factor (NGF) is synthesized in male germ cells. The NGF receptor (NGFR) mRNA was found in the Sertoli cells of rat testis. Hypophysectomy increased both NGFR mRNA in testis and the number of NGFR hybridizing cells in seminiferous tubules. This was suppressed by treatment with chorionic gonadotropin or testosterone, but not with follicle-stimulating hormone. The NGFR mRNA also increased after destruction of Leydig cells or blocking of the androgen receptor. This suggests that NGF produced by male germ cells regulates testicular function in an androgen-modulated fashion by mediating an interaction germ and Sertoli cells. 相似文献
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为了探讨大豆异黄酮（SI）对去卵巢大鼠脾脏中神经生长因子（NGF）、白细胞介素2（IL-2）蛋白表达的影响,本研究在成功建立去卵巢大鼠模型的基础上,对去卵巢大鼠分别隔天皮下注射高（1.5 mg·kg-1）、中（1.0 mg·kg-1）、低（0.5 mg·kg-1 ）剂量的SI,假手术组（仅手术而不去卵巢）和溶媒组（去卵巢）大鼠隔天皮下注射溶媒剂（乙醇）。补充SI至14 d和42 d时,每组随机剖杀5只大鼠,采用免疫组织化学方法,对大鼠脾脏NGF、IL-2蛋白的表达变化进行研究。结果表明,脾脏中广泛分布着NGF、IL-2蛋白,主要分布于被膜下方的红髓区,在白髓分布量极少。去卵巢后,大鼠脾脏中NGF、IL-2蛋白的表达强度和阳性细胞数目均显著下降,而且随着去除卵巢时间的延长下降加剧。体外补充SI后14 d,各剂量组和42 d低、中剂量组仅有部分恢复,变化不显著;补充高剂量SI 42 d后,脾脏NGF、IL-2蛋白的表达强度和阳性细胞数目基本恢复至假手术组的水平。大豆异黄酮能上调NGF、IL-2蛋白在脾脏内的表达,并呈现时间和剂量的依赖性。 相似文献
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Gene transfer and molecular cloning of the human NGF receptor 总被引：34，自引：0，他引：34
M V Chao M A Bothwell A H Ross H Koprowski A A Lanahan C R Buck A Sehgal 《Science (New York, N.Y.)》1986,232(4749):518-521
Nerve growth factor (NGF) and its receptor are important in the development of cells derived from the neural crest. Mouse L cell transformants have been generated that stably express the human NGF receptor gene transfer with total human DNA. Affinity cross-linking, metabolic labeling and immunoprecipitation, and equilibrium binding with 125I-labeled NGF revealed that this NGF receptor had the same size and binding characteristics as the receptor from human melanoma cells and rat PC12 cells. The sequences encoding the NGF receptor were molecularly cloned using the human Alu repetitive sequence as a probe. A cosmid clone that contained the human NGF receptor gene allowed efficient transfection and expression of the receptor. 相似文献
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Expression of the beta-nerve growth factor gene in hippocampal neurons 总被引：16，自引：0，他引：16
C Ayer-LeLievre L Olson T Ebendal A Seiger H Persson 《Science (New York, N.Y.)》1988,240(4857):1339-1341
In situ hybridization with complementary DNA probes for nerve growth factor (NGF) was used to identify cells containing NGF messenger RNA in rat and mouse brain. The most intense labeling occurred in hippocampus, where hybridizing neurons were found in the dentate gyrus and the pyramidal cell layer. The neuronal identity of NGF mRNA-containing cells was further assessed by a loss of NGF-hybridizing mRNA in hippocampal areas where neurons had been destroyed by kainic acid or colchicine. RNA blot analysis also revealed a considerable decrease in the level of NGF mRNA in rat dentate gyrus after a lesion was produced by colchicine. This lesion also caused a decrease in the level of Thy-1 mRNA and an increase in the level of glial fibrillary acidic protein mRNA. Neuronal death was thus associated with the disappearance of NGF mRNA. These results suggest a synthesis of NGF by neurons in the brain and imply that, in hippocampus, NGF influences NGF-sensitive neurons through neuron-to-neuron interactions. 相似文献
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The trk proto-oncogene product: a signal transducing receptor for nerve growth factor. 总被引：108，自引：0，他引：108
D R Kaplan B L Hempstead D Martin-Zanca M V Chao L F Parada 《Science (New York, N.Y.)》1991,252(5005):554-558
The trk proto-oncogene encodes a 140-kilodalton, membrane-spanning protein tyrosine kinase (p140prototrk) that is expressed only in neural tissues. Nerve growth factor (NGF) stimulates phosphorylation of p140prototrk in neural cell lines and in embryonic dorsal root ganglia. Affinity cross-linking and equilibrium binding experiments with 125I-labeled NGF indicate that p140prototrk binds NGF specifically in cultured cells with a dissociation constant of 10(-9) molar. The identification of p140prototrk as an NGF receptor indicates that this protein participates in the primary signal transduction mechanism of NGF. 相似文献
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神经生长因子NGF及其受体TrkA在雌性水牛生殖器官的表达定位 总被引：1，自引：0，他引：1
为研究神经生长因子NGF及其受体TrkA在广西雌性水牛生殖器官中表达定位情况,运用免疫组织化学ABC法对处于发情周期不同阶段(卵泡期、黄体期)成年水牛的卵巢、子宫、输卵管NGF、TrkA分别进行染色定位.结果表明:NGF/TrkA阳性细胞在卵巢主要见于卵泡内膜细胞、颗粒细胞及黄体细胞;在子宫主要见于子宫内膜上皮细胞、腺... 相似文献
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Molecular cloning of a gene sequence regulated by nerve growth factor 总被引：22，自引：0，他引：22
Nerve growth factor (NGF) is essential for the development and differentiation of sympathetic or sensory neurons. A complementary DNA was cloned that corresponds to a gene sequence induced more than 50-fold in a cultured target cell line of pheochromocytoma cells (PC12 cells) 5 hours after the addition of NGF. The induced messenger RNA encodes a 90,000-dalton polypeptide that may represent one of the primary events in NGF-induced differentiation of neurons. 相似文献
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Nerve growth factor(NGF) binds to TrkA and forms a NGF/TrkA complex at the cell surface,which is then internalized into signaling endosomes and promotes neuronal survival and neurite outgrowth.The small GTPase Rab5 is reported to localize on the plasma membrane and early endosomes,regulating endosome fusion.It was reported that endogenous Rab5 function may need to be suppressed during NGF-induced neurite outgrowth and cell differentiation.Two Rab5 homologs(MoRab5A:MGG_06241 and MoRab5B:MGG_01185) were characterized from the rice blast fungus Magnaporthe oryzae,and MoRab5 B was identified as the Rab5 ortholog promoting early endosomal fusion,while MoRab5 A specialized to perform a non-redundant function in endosomal sorting.In this study,we examined whether MoRab5 A and MoRab5 B play different roles in NGF-induced neurite outgrowth and cell differentiation in PC12 cells(a rat pheochromocytoma cell line).Our data showed that MoRab5 B is a negative regulator of NGF signaling and neurite outgrowth in PC12 cells,similar to human Rab5(hRab5).MoRab5B:WT inhibits NGF signaling-dependent neurite outgrowth while the dominant-negative MoRab5 B mutant(MoRab5B:DN) enhances NGF signaling and neurite outgrowth.In contrast,MoRab5A:WT and MoRab5A:DN both significantly promote NGF-induced neurite outgrowth,indicating that MoRab5 B is more similar to hRab5 than MoRab5 A in the regulation of NGF signal transduction. 相似文献
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A nerve growth factor-induced gene encodes a possible transcriptional regulatory factor 总被引：136，自引：0，他引：136
J Milbrandt 《Science (New York, N.Y.)》1987,238(4828):797-799
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为了探讨神经干细胞(Neural stem cells,NSCs)在体外培养中的生物学特性,研究不同细胞因子对NSCs分化的影响,试验对大鼠胎儿神经干细胞进行了分离培养,并研究了10,50和100 ng/mL的神经生长因子(nerve growth factor,NGF)、脑源性神经营养因子(brain derived neruotrophic factor,BDNF)和胶质源性神经生长因子(glial cell line-derived neurotrophic factor,GDNF)对NSCs的定向诱导分化作用。结果表明,大鼠胎儿NSCs可在体外增殖并形成典型的神经球,指数增长期在传代后的第4~5天;10和50 ng/mL的NGF、BDNF和GDNF对NSCs的诱导分化作用不明显,100 ng/mL的NGF、BDNF和GDNF可诱导NSCs分化为神经元或胶质细胞。说明NGF和BDNF可诱导NSCs向神经元方向分化,GDNF诱导其向胶质细胞分化。 相似文献
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雌激素对老年大鼠小脑ER、ChAT、NGF表达的影响 总被引：6，自引：0，他引：6
【目的】 探讨雌激素对大鼠小脑内雌激素受体（ER）、神经生长因子（NGF）和胆碱乙酰转移酶（ChAT）表达的影响。【方法】运用超敏感的免疫组织化学SP法，以老年SD大鼠小脑为研究对象，通过补充17β－雌二醇对ER、NGF和ChAT在小脑中的表达和分布变化进行研究。【结果】ER、NGF和ChAT免疫阳性反应物分布于小脑的蒲肯野氏细胞层、小脑齿状核、小脑间位核和小脑室顶核，ER阳性产物主要定位于细胞胞浆和突起中，也存在于胞膜和胞核中。老年大鼠小脑皮质及小脑核中ER、NGF和ChAT的表达强度及阳性细胞数量总趋势是显著降低，而补充17β－雌二醇后三种阳性产物的强度和阳性细胞数目显著回升，蒲肯野氏细胞的阳性突起长度和数量也呈此变化趋势。【结论】雌激素可促进NGF和ChAT的表达，在维持和保护小脑神经元的结构和功能中发挥了重要作用；另外ER、NGF和ChAT表达变化的相似性提示三者在雌激素对小脑的作用中是相互调节和影响的，同时表明雌激素在小脑发挥作用可能既通过基因组机制，也通过非基因组机制途径。 相似文献
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Chimeric NGF-EGF receptors define domains responsible for neuronal differentiation 总被引：15，自引：0，他引：15
To determine the domains of the low-affinity nerve growth factor (NGF) receptor required for appropriate signal transduction, a series of hybrid receptors were constructed that consisted of the extracellular ligand-binding domain of the human epidermal growth factor (EGF) receptor (EGFR) fused to the transmembrane and cytoplasmic domains of the human low-affinity NGF receptor (NGFR). Transfection of these chimeric receptors into rat pheochromocytoma PC12 cells resulted in appropriate cell surface expression. Biological activity mediated by the EGF-NGF chimeric receptor was assayed by the induction of neurite outgrowth in response to EGF in stably transfected cells. Furthermore, the chimeric receptor mediated nuclear signaling, as evidenced by the specific induction of transin messenger RNA, an NGF-responsive gene. Neurite outgrowth was not observed with chimeric receptors that contained the transmembrane domain from the EGFR, suggesting that the membrane-spanning region and cytoplasmic domain of the low-affinity NGFR are necessary for signal transduction. 相似文献
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利用免疫组化SP法,检测了去势及去势后补充雄激素大鼠嗅球中雄激素受体(A ndrogen recep-tors,AR)和神经生长因子(N erve grow th factor,NGF)蛋白的表达情况,探讨了雄激素对嗅球的作用机制。结果表明,睾丸摘除组大鼠嗅球内AR与NGF蛋白的表达显著减少;睾丸摘除并用睾酮替代组大鼠嗅球内2种蛋白的表达接近正常水平。说明去睾丸大鼠由于缺乏内源性雄激素,会引起嗅球内AR和NGF蛋白表达减少,而补充外源性雄激素可缓解或抑制这一变化。 相似文献
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The chick ciliary ganglion receives a nonvascular symathetic innervation in addition to the well-known cholinergic one; fluorescent, varicose adrenergic fibers form pericelluar baskets. Adrenergic fibes were identified electron microscopically in ganglia fixed with potassium permanganate. The fibers degenerate after injection of 6-hydroxydopamine. No true synaptic relationships involving adrenergic varicosities and ganglion cells or cholinergic terminals were demonstrable. The distribution of the adrenergic fibers suggests a kind of "distance à synapse" with the choroidal cells or with the preganglionic fibers (or both). The adrenergic innervation might provide a modulation of the cholinergic transmission. 相似文献
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Witten IB Lin SC Brodsky M Prakash R Diester I Anikeeva P Gradinaru V Ramakrishnan C Deisseroth K 《Science (New York, N.Y.)》2010,330(6011):1677-1681
Cholinergic neurons are widespread, and pharmacological modulation of acetylcholine receptors affects numerous brain processes, but such modulation entails side effects due to limitations in specificity for receptor type and target cell. As a result, causal roles of cholinergic neurons in circuits have been unclear. We integrated optogenetics, freely moving mammalian behavior, in vivo electrophysiology, and slice physiology to probe the cholinergic interneurons of the nucleus accumbens by direct excitation or inhibition. Despite representing less than 1% of local neurons, these cholinergic cells have dominant control roles, exerting powerful modulation of circuit activity. Furthermore, these neurons could be activated by cocaine, and silencing this drug-induced activity during cocaine exposure (despite the fact that the manipulation of the cholinergic interneurons was not aversive by itself) blocked cocaine conditioning in freely moving mammals. 相似文献