中西药结合促进心梗后大鼠胆碱能神经的恢复

目的：观察葛根素与神经生长因子联合应用对大鼠心肌梗死后去胆碱能神经支配的影响，以证实二者联合应用对心梗后大鼠胆碱能神经功能恢复的作用。方法：实验用SD大鼠32只，分为正常组、心肌梗死组、神经生长因子组及联合用药组。术后2d取材，以Karnovsky-Roots法，显示胆碱能神经纤维，应用多功能真彩色病理图像分析系统分析胆碱能神经纤维密度。结果：心肌梗死组存活心肌中胆碱能神经纤维密度最低，联合用药组胆碱能神经纤维密度最高。结论：葛根素与神经生长因子联合应用能够明显减缓大鼠心肌梗死后的去胆碱能神经支配，促进神经功能的恢复。     

大鼠心肌梗塞后梗塞区胆碱能神经支配的变化

目的：探讨大鼠心肌梗塞区胆碱能神经支配的变化。方法：实验用20只大鼠，以组织化学Karnovsky-Roots法显示胆碱能神经纤维。应用多功能图像分析仪测定梗塞区胆碱能神经纤维密度。结果：大鼠心肌梗塞后4天，梗塞区胆碱能神经纤维密度显著下降；梗塞后14天，梗塞区胆碱能神经纤维完全消失；梗塞后120天，心肌梗塞区的部分区域出现胆碱能神经纤维，结论：大鼠心肌梗塞后14天，梗塞区发生完全的去胆碱能神经支配，120天后部分区域出现胆碱能神经再支配。     

生长激素释放肽对心衰大鼠植物神经重构的影响

本研究观察了生长激素释放肽(GHRP)的应用对心衰动物胆碱能神经和肾上腺素能神经支配的影响。Wistar大鼠50只,随机分为:假手术组10只;GHRP组30只;模型组10只。心衰模型成功后4周,Karnovsky-Roots法及免疫组织化学方法分别显示心肌胆碱能神经纤维及肾上腺素能免疫阳性纤维,应用多功能真彩色病理图像分析系统分析两种神经纤维密度。结果显示,模型组大鼠心肌中胆碱能神经纤维和肾上腺素能神经纤维密度明显低于假手术组(P<0.01);GHRP组大鼠心肌中两种神经纤维密度较模型组明显增高(P<0.01),但略低于假手术组神经纤维密度(P<0.05)。上述研究表明GHRP可延缓大鼠心衰后的去神经支配,改善神经重构。     

神经生长因子促进老年鼠大脑皮质胆碱能纤维损伤后再生

目的：探讨神经生长因子（nerve growth factor,NGF)对老年鼠大脑皮质胆碱能神经纤维损伤后再生的影响。方法：老年SD大鼠顶皮质切一宽2mm的冠状切口,侧脑室注射NGF,AChE纤维染色结合体视系分析正常组,损伤对照组和NGF用药组切口嘴,尾侧区的胆碱能纤维的再生情况。结果：损伤对照组损伤1个月后,嘴侧AChE阳性纤维增生至正常111．44％,尾侧纤维减少至正常67．14％;NGF用药组嘴侧纤维密度比损伤对照组增多,为正常145．93％,尾侧纤维为正常127．95％,结论：提示NGF对老年乳类皮质胆碱能纤维后损伤再生具有一定促进作用。     

神经生长因子偶联物对老年性痴呆动物模型的保护作用

目的　探讨神经生长因子偶联物 (NGF -Tf)对老年性痴呆 (AD)大鼠的影响 .方法　以手术切断大鼠双侧隔 -海马胆碱能通路的方法建立AD动物模型 ,每天从大鼠尾静脉注射NGF -Tf .通过水迷路试验观察大鼠的记忆和方向辨别能力 ;对海马和隔区行神经组织学检查 ;应用酶组织化学技术显示相应区域的ChAT ,采用计算机病理图像分析系统测定酶活性以判断其胆碱能功能状态 .结果　水迷路试验中 ,NGF -Tf组在 10s内抵达平台的正确反应平均数提高 (p <0 .0 5 ) .光镜下 ,NGF -Tf组隔区仅见轻微萎缩性改变 ,而模型组隔区萎缩性改变较明显 ,表现为神经元数目明显减少 ,细胞轮廓不清 ,有胶质细胞增生 ;正常对照组、NGF -Tf组和模型组的海马区未见明显病理性改变 .ChAT染色统计结果显示 ,正常对照组、NGF -Tf组大鼠的海马区及隔区IOD值与模型组比较 ,均有显著性差异 (p <0 .0 1) .结论　NGF -Tf能穿透血脑屏障 ,有效防止模拟AD病变的大鼠的基底前脑胆碱能神经元的变性和死亡 ,改善其记忆和方向辨别能力 ,促进其胆碱能神经元的功能恢复     

神经节苷脂神经生长因子促进周围神经再生的实验研究

目的研究神经生长因子(Nerve Growth Factor,NGF)联合神经节苷脂(GangliosideM1,GM1)对周围神经再生的作用。方法硅胶管套接大鼠坐骨神经,将NGF、GM1、生理盐水、GM1 NGF混合液分别加入硅胶管内,术后4周、8周行组织学观察。结果实验组再生神经有髓神经纤维、髓鞘厚度均高于对照组,GM1 NGF组均高于其他三组,差异有显著性(<0.01)。结论NGF、GM1能促进运动神经元轴突再生。GM1介导NGF促进运动神经元轴突再生,表现出良好的生物学效应。     

神经生长因子的研究现状

<正> 神经生长因子(Nerve Growth Factor, NGF)对周围神经系统的感觉和交感神经细胞的生存、分化及功能活动至关重要。近来有证据说明神经生长因子对中枢神经系统胆碱能神经元的发育及功能也有重要作用。神经生长因子及神经生长因子信使核糖核酸(NGF mRNA)在脑内海马及皮质中的含量最高。切断大鼠隔-海马通路后,将神经生长因子引入脑内可防止损伤引起的基底前脑胆碱能神经元的萎缩及坏死,这提示神经生长因子对累及胆     

纳米转基因技术可用于大鼠心梗后血管再生

目的 探讨包载VEGF165质粒的聚乳酸-乙醇酸(PLGA)纳米粒子对大鼠心肌梗死后血管再生治疗的可行性.方法 制备大鼠心梗模型36只,实验组24只、对照组12只,术后1周在梗死区和与正常心肌交界处注射pVEGF165-PLGA纳米粒子和pVEGF165.应用RT-PCR和免疫组化检测血管内皮生长因子在不同的时间点(3、7、11、14和21 d)的表达;组织切片观察梗死区血管形成特点及其密度;以及纳米粒子对人体的毒副作用.结果 与对照组相比,实验组VEGF可在心肌组织持续稳定表达;梗死区血管内皮细胞增生活跃,再生血管数量增加.注射48 h后心肌细胞核内可见纳米粒子,8周后组织活检未见血管瘤.结论 PLGA纳米粒子有效介导pVEGF165转染心肌,并通过心肌细胞表达VEGF165,促进缺血区心肌组织的血管再生.     

葛根素对大鼠心肌梗死后梗死部位肾上腺素能神经纤维的影响

目的观察葛根素对大鼠心肌梗死后梗死部位。肾上腺素能神经纤维分布的影响，以求证实葛根索的神经保护作用。方法Wister大鼠120只，分为假手术组、心肌梗死模型组和葛根素组。分别于术后6h、2、4、7、14时取材，应用免疫组织化学方法，显示肾上腺素能神经纤维，应用多功能真彩色病理图像分析系统分析。肾上腺素能神经纤维的密度。结果心肌梗死模型组大鼠在术后6h、2、4、7、14时，梗死区肾上腺素能神经纤维密度均比假手术组明显降低（P〈0．01）。葛根素组大鼠在术后7、14d时，梗死区。肾上腺素能神经纤维密度较心肌梗死模型组明显增多（P〈0．01）；与假手术组相比无显著差异（P〉0．05）。结论葛根素能干预大鼠心肌梗死后的肾上腺素能神经纤维分布减少，具有神经保护作用。     

Neurturin和NGF联合应用对AD模型鼠基底前脑NGFR阳性神经元的保护作用

本研究目的是探讨neurturin和神经生长因子(NGF)联合应用对穹窿-海马伞(FF)切断后基底前脑胆碱能神经元的保护作用。将这两种因子联合注射到FF切断的大鼠侧脑室,注射一个月后,取脑进行免疫组化结合图像分析方法对内侧隔核(MS)和斜角带核垂直支(VDB)的神经生长因子受体(NGFR)阳性神经元存活情况进行比较分析。结果表明:FF切断一个月后,损伤组损伤侧MS和VDB的NGFR阳性神经元大量减少(分别减少64.8％和51.4％),MS和VDB的NGFR阳性细胞的面积和周长显著降低(P<0.01),OD值显著增高(P<0.01);NGF组损伤侧NGFR阳性神经元受到保护,NGFR阳性经元数显著高于损伤组损伤侧(P<0.01);联合组损伤侧NGFR阳性神经元也受到保护(MS和VDB细胞数分别只下降7.3％和15.4％),与损伤组损伤侧比较NGFR阳性细胞数增加了57.4％和36.0％(P<0.01),也明显高于NGF组(P<0.05);细胞形态学参数明显改善(P<0.05),细胞膜受体含量显著提高(P<0.05)。结果提示,neurturin和NGF联合应用和NGF单独应用均能不同程度地保护基底前脑胆碱能神经元,联合应用效果更佳。     

Nerve growth factor improves spatial learning and restores hippocampal cholinergic fibers in rats withdrawn from chronic treatment with ethanol

The cholinergic septohippocampal pathway has long been known to be important for learning and memory. Prolonged intake of ethanol causes enduring memory deficits, which are paralleled by partial depletion of hippocampal cholinergic afferents. We hypothesized that exogenous supply of nerve growth factor (NGF), known to serve as a trophic substance for septal cholinergic neurons, can revert the ethanol-induced changes in the septohippocampal cholinergic system. Adult rats were given a 20% ethanol solution as their only source of fluid for 6 months. During the first 4 weeks after the animals were withdrawn from ethanol, they were intraventricularly infused with either NGF or vehicle alone via implanted osmotic minipumps. The vehicle-infused withdrawn animals showed impaired performance on a spatial reference memory version of the Morris water maze task, both during the task acquisition and on the retention test. In contrast, NGF-treated withdrawn rats were able to learn the task as well as controls, and significantly outperformed the vehicle-infused withdrawn rats. The histological analysis revealed that, in the latter group, the length density of fibers immunoreactive to choline acetyltransferase was reduced relative to control values by approximately 25%, as measured in the dentate gyrus and regio superior of the hippocampal formation. However, in NGF-treated withdrawn rats, the length density of these fibers was identical to that of control rats. These data provide support to the notion that NGF is capable of ameliorating memory deficits and restoring septohippocampal cholinergic projections following chronic treatment with ethanol. Electronic Publication     

神经生长因子/胶源性神经营养因子基因修饰神经前体细胞单独和联合移植促进阿尔茨海默病模型鼠海马胆碱能纤维网的重建

目的 :观察神经生长因子 (Nervegrowthfactor,NGF) /胶源性神经营养因子 (Glialcellline derivedneurotroph icfactor,GDNF)基因修饰神经前体细胞 (Neuralprogenitorcell,NPC)单独和联合移植对阿尔茨海默病 (Alzheimer’sdisease,AD)模型鼠海马胆碱能纤维网的促重建作用。方法 :将NGF/GDNF基因修饰的NPC单独和联合移植入FF切断的大鼠侧脑室内。移植后三周取海马切片进行AchE纤维组织化学染色。结果 :CA1区和齿状回的NGF组、GDNF组和NGF +GDNF组的AchE纤维数分别为 3 2 %和 5 0 %、1 8%和 2 4 %、2 4 %和 5 8% ,明显高于损伤组(4 %和 6% )和NPC组 (7%和 9% ) ,P均 <0 .0 1 ;NGF组也高于GDNF组 (P <0 .0 5和P <0 .0 1 )。结论 :NGF/GDNF基因修饰的NPC单独和联合移植均能不同程度地促进AD模型鼠海马胆碱能纤维网的重建 ,其中NGF组和NGF +GDNF组作用大于GDNF组     

Nerve growth factor promotes development of the rat septo-hippocampal cholinergic projection in vitro

There is now widespread evidence indicating that nerve growth factor (NGF) is involved in the function of central cholinergic neurons. Its possible role in the establishment of cholinergic fiber connectivities was studied in co-cultures of rat septum and hippocampus. Application of 100 ng/ml NGF greatly increased the number of acetylcholinesterase (AChE)-positive fibers which invaded the hippocampal slices, an effect which was accompanied by a more than 6-fold elevation of the two major cholinergic enzymes, choline acetyltransferase and AChE. In contrast, application of anti-NGF antiserum, but not a non-immune serum, reduced the number of AChE-positive fibers which grew into and remained within the hippocampal slices. Since no diffuse outgrowth of AChE-positive fibers from the septum was observed following application of NGF, these results suggest that NGF plays a role in the stabilization and long-term maintenance of the cholinergic septo-hippocampal projection in vitro.     

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.     

Amelioration of cholinergic neurons dysfunction in aged rats depends on the continuous supply of NGF

The present study was designed to examine whether NGF-induced improvement in morphology of senile basal forebrain cholinergic neurons persist after discontinuation of NGF treatment. Trophic effect of continuous intraventricular infusion of NGF was tested in the 4- and 28 months old male Wistar rats immediately after cessation of NGF and 3 or 6 weeks after termination of treatment. Immunohistochemical procedure for ChAT, TrkA, and p75(NTR) receptor has been applied to identify cholinergic cells in the basal forebrain structures. Using the quantitative image analyzer, morphometric and densitometric parameters of cholinergic cells were measured. In untreated 28-month-old rats a reduction in the number, size and intensity of staining of cholinergic neurons was observed in all basal forebrain structures. NGF significantly improved morphological parameters of ChAT- and TrkA-positive cells in aged rats. In 28-month-old rats tested within 3 and 6 weeks after discontinuation of infusion a renewed progressive deterioration of cholinergic phenotype of basal forebrain neurons was observed when compared with the NGF-treated immediately tested group. The parallel staining for p75(NTR) revealed normal morphology of the basal forebrain neurons, despite of the age of rats or the NGF treatment. Analysis of Nissl stained sections also showed that 28-month-old rats did not display significant losses of neurons in the basal forebrain when compared with the young animals. These findings demonstrate that senile impairment of cholinergic neurons is induced by a loss of cholinergic phenotype rather than an acute degeneration of cell bodies. NGF may be beneficial in enhancing cholinergic neurochemical parameters, but the protective effects seem to be dependent on the continuous supply of NGF.     

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     

Transplants of NGF-secreting fibroblasts restore stimulus-evoked activity in barrel cortex of basal-forebrain-lesioned rats

Cholinergic nuclei in the basal forebrain supply the cerebral cortex with acetylcholine (ACh). Depletion of cholinergic fibers following basal forebrain lesion results in reduced stimulus-evoked functional activity in rat barrel cortex in response to whisker stimulation. We showed previously that exogenous delivery of nerve growth factor (NGF) to the lateral ventricle restores reduced functional activity toward normal despite persistent reductions in cortical cholinergic activity. Gene transfer of therapeutic peptides using genetically engineered cells allows for localized and biological delivery of compounds to the CNS, circumventing systemic administration or repetitive invasive surgery. In this study, we grafted genetically engineered fibroblasts that secrete NGF (NGF+) into three CNS loci of rats with unilateral basal forebrain lesions, along with control fibroblasts (NGF-) that did not secrete NGF. Only NGF+ fibroblasts grafted into ACh-depleted somatosensory cortex resulted in improvement of functional activity following cholinergic depletion. NGF+ fibroblast transplants into the lateral ventricle or basal forebrain did not improve functional activity nor did NGF- fibroblasts in any site. Similar to our previous experiments using intraventricular NGF injections, despite improvements in functional activity, the affected barrel cortex remained depleted of acetylcholinesterase-stained fibers following insertion of NGF+ fibroblasts. These data support the idea that NGF can act directly on the cerebral cortex following reductions in cholinergic innervation. The mechanism of NGF action is elusive, however, since the presence of its high-affinity receptor, trkA, in the cerebral cortex is controversial.     

NGF/GDNF基因修饰神经干细胞移植对AD模型鼠前脑胆碱能神经元的保护作用

目的　观察NGF GDNF基因修饰神经干细胞 (NSC)单独和联合移植对穹窿海马伞 (FF)切断后胆碱能神经元的保护作用。　方法　将两种基因修饰的NSC单独和联合移植入FF切断的大鼠侧脑室。移植后 3周取脑行ChAT免疫组织化学染色 ,用Student NewmanKaels方法对内侧隔核 (MS)和斜角带垂直支 (VDB)的ChAT阳性细胞数 (损伤侧与正常侧的百分比 )进行计数分析。　结果　NGF组伤侧MS的ChAT阳性神经元数为 81% ,明显高于损伤组 (34% )、NSC组 (36 % )和GDNF组 (5 0 % ) ,P <0 0 1;NGF GDNF组为 6 8% ,明显高于损伤组和NSC组 (P <0 0 1) ,亦高于GDNF组 (P <0 0 5 ) ;GDNF组与损伤组和NSC组相比 ,有统计学意义 (P <0 0 5 )。NGF组和NGF GD NF组伤侧VDB的ChAT阳性神经元数分别为 80 %和 72 % ,明显高于损伤组 (5 6 % )和NSC组 (5 2 % ) ,P <0 0 1,亦高于GDNF组 (5 9% ) ,P <0 0 5 ;GDNF组与损害组和NSC组相比无明显差异 (P >0 0 5 )。　结论　NGF GDNF基因修饰NSC单独和联合移植均能不同程度地保护损伤的ChAT阳性神经元 ,NGF组和NGF GDNF组作用较大 ,GDNF组作用较小。