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1.
目的探讨利福平抗鱼藤酮诱导帕金森病大鼠模型多巴胺神经元凋亡的作用。方法给SD大鼠背部皮下注射鱼藤酮1.5 mg/(kg.d)3周使其黑质多巴胺神经元发生凋亡,同时经灌胃给予利福平30 mg/(kg.d)干预,并通过对大鼠中脑切片进行TUNEL及Bax、Bcl-2和Caspase-3的免疫活性检测以明确利福平抗多巴胺神经元凋亡的作用。结果长期低剂量接触鱼藤酮可诱导SD大鼠中脑黑质部位出现凋亡细胞增加以及Bax、Bcl-2、Caspase-3的免疫活性的改变(P均<0.01),而应用利福平后可明显减轻这些变化(P均<0.01)。结论利福平具有抗鱼藤酮帕金森病大鼠模型的多巴胺神经元凋亡的作用,且此作用是通过上调Bcl-2和Bax的比值、抑制caspase通路而实现的。  相似文献   

2.
依达拉奉对培养乳鼠海马神经元缺氧复氧损伤的保护作用   总被引:1,自引:0,他引:1  
目的:探讨依达拉奉对海马神经元缺氧复氧损伤的保护作用及其机制。方法:制备培养乳鼠海马神经元缺氧复氧损伤模型,分别用依达拉奉1、10、100、300μmol·L-1干预后研究依达拉奉对脂质过氧化及细胞凋亡的作用。结果:海马神经元在缺氧复氧损伤后,依达拉奉干预能降低脂质过氧化产物丙二醛(MDA)含量,增加细胞内超氧化物歧化酶(SOD)活性,减少神经元凋亡。结论:缺氧复氧损伤后,依达拉奉具有清除氧自由基、抑制脂质过氧化及降低细胞凋亡率的作用。  相似文献   

3.
目的研究丁基苯酞(dl-3n-butylphthalide,NBP)对由MPTP诱导的C57BL/6小鼠帕金森模型中脑黑质多巴胺能神经元数及TH、TNF-α蛋白表达的影响,进一步探讨其保护机制。方法 24只C57BL/6小鼠,随机分成3组:正常对照组,MPTP组,NBP治疗组。MPTP腹腔注射法制备帕金森模型,免疫组织化学法观察中脑黑质TH阳性神经元细胞数,蛋白质印迹法观察中脑黑质TH、TNF-α蛋白含量的变化。结果 (1)与正常对照组比较,MPTP组可见帕金森病小鼠中脑黑质TH阳性神经元明显减少(P0.01);与MPTP组比较,NBP治疗组帕金森病小鼠中脑黑质TH阳性神经元数目明显增加(P0.01);(2)与正常对照组比较,MPTP组帕金森病模型小鼠中脑黑质TH蛋白表达减少(P0.01),而TNF-α蛋白表达增加(P0.05);(3)与MPTP组比较,NBP治疗组帕金森病模型小鼠中脑黑质TH蛋白表达明显增加(P0.01),而TNF-α蛋白表达减少(P0.05)。结论丁基苯酞可能通过提高中脑黑质中TH的含量及减少TNF-α炎性介质表达发挥对MPTP所致C57BL/6小鼠帕金森模型的神经元保护作用。  相似文献   

4.
目的探讨自由基清除剂依达拉奉对脂多糖(LPS)诱导的多巴胺能神经元变性的保护作用。方法18只大鼠随机分成3组:磷酸缓冲液(PBS)对照组、生理盐水+LPS组(生理盐水治疗组)和依达拉奉+LPS组(依达拉奉治疗组)。黑质内立体定向注射15μg(2μl)LPS或PBS,采用免疫组织化学方法观察注射后14d大鼠黑质酪氨酸羟化酶(TH)阳性细胞的数量以及小胶质细胞的形态学变化。结果与对照组相比,生理盐水治疗组TH阳性细胞数减少到对侧的16%(P<0.05),细胞突触也明显减少;依达拉奉治疗组TH阳性细胞数较生理盐水治疗组明显增多,为对侧的59%(P<0.05),部分突触存在。两治疗组小胶质细胞形态无明显差异。结论依达拉奉显著抑制LPS诱导的黑质多巴胺能神经元变性。  相似文献   

5.
目的 探讨依达拉奉对脑缺血神经细胞损伤的保护作用和对凋亡的影响.方法 实验目标为出生24 h内SD乳鼠的脑细胞,培养7 d后进行分组培养,分别检测各组的指标,包括神经细胞存活率、LDH的漏出率、细胞凋亡率等,进行统计学分析.结果 依达拉奉组与正常对照组相比存活率无显著下降(P>0.05),正常对照组与其他损伤组细胞存活率比较显著下降(P<0.05).细胞凋亡率观察依达拉奉组与正常对照组相比无显著下降(P>0.05),药物损伤组、低浓度异丙酚组、中浓度异丙酚组、高浓度异丙酚组与正常对照组比较均较高(P<0.05).结论 依达拉奉是一种自由基清除剂,抑制细胞膜过氧化,增强细胞总抗氧化能力,提高细胞稳定性,对脑缺血神经细胞损伤起到保护作用,减少细胞凋亡率,增加细胞存活率.  相似文献   

6.
离体帕金森病动物模型制作的研究   总被引:7,自引:1,他引:6  
目的 :研究用 6 -羟多巴胺 (6 - OHDA)对中脑黑质多巴胺能神经元的选择性神经毒性作用建立离体帕金森病实验模型的方法。方法 :用 6 - OHDA(浓度分别为 0 .0 1m M、 0 .0 5 m M、 0 .1m M)孵育大鼠离体脑片 1小时 ,用抗酪氨酸羟化酶免疫组织化学方法观测黑质阳性细胞体及突起的变化。结果 :随着 6 - OHDA浓度的增加 ,离体脑片黑质 TH阳性细胞突起及纤维数逐渐减少。结论 :6 - OHDA孵育大鼠离体脑片可复制成帕金森病离体模型。  相似文献   

7.
目的观察α-硫辛酸(LA)对鱼藤酮致帕金森(PD)大鼠模型黑质多巴胺能神经元的保护作用。方法健康成年雄性Wistar大鼠背部皮下注射鱼藤酮制备PD大鼠模型,药物治疗组同时给予大鼠腹腔注射LA。采用分光光度法检测大鼠脑内丙二醛(MDA)和还原型谷胱甘肽(GSH),Western blot检测大鼠中脑黑质及纹状体酪氨酸羟化酶(TH)的表达变化。结果与对照组相比,鱼藤酮组大鼠纹状体中MDA明显增高(P<0.01)而GSH含量明显降低(P<0.01),TH蛋白在黑质和纹状体与对照组比较明显降低(P<0.05);LA干预后与鱼藤酮组相比MDA明显降低及GSH明显增高(P<0.05),TH蛋白表达明显增加(P<0.05)。结论氧化应激在PD发病中起着非常重要的作用,LA能有效减轻PD大鼠脑内氧化应激损伤、保护脑内多巴胺能神经体系,同时改善PD样症状。  相似文献   

8.
目的研究鱼藤酮对大鼠脑内多巴胺能神经元的毒性作用机制。方法健康成年雄性Wistar大鼠背部皮下注射鱼藤酮制备帕金森病动物模型。采用免疫细胞化学、透射电镜技术及分光光度法技术检测大鼠脑内多巴胺能神经元的损伤及纹状体中氧化应激参数的改变。结果鱼藤酮组大鼠中脑酪氨酸羟化酶(TH)免疫反应阳性神经元数明显少于对照组(P<0.01),纹状体中TH免疫反应强度明显降低(P<0.05),透射电镜可见鱼藤酮组黑质多巴胺能神经元内线粒体损伤,树突变性,其内微粒、微管聚集,同时纹状体发生了明显的氧化损伤。结论氧化应激和超微结构改变是鱼藤酮对大鼠脑内多巴胺能神经元损伤的主要发病机制。  相似文献   

9.
鱼藤酮致帕金森病大鼠行为学与黑质病理损伤的关系   总被引:1,自引:0,他引:1  
目的 研究鱼藤酮所致大鼠帕金森病模型行为学变化及与黑质多巴胺能神经损伤的关系.方法 Wistar大鼠每日颈背部皮下注射鱼藤酮油乳液(2 mg/kg),按所建立的评分标准记分,有记分即终止给药.中脑黑质病理切片行酪氨酸羟化酶(TH)免疫组化染色.结果 鱼藤酮用药36 d,96%的大鼠出现行为学改变,记分为1~2分者51%,4~6分者15%,8~10分者30%.约3%不敏感.记2分及以上的动物,黑质细胞缺失显著.从黑质TH染色细胞胞体的形态及突起损伤程度见,随着行为学记分的增加损伤加剧.结论 动物行为变化主要是黑质多巴胺能神经受损和缺失所引起.行为学记分能相应反映黑质多巴胺能神经元的损伤程度.  相似文献   

10.
目的探索依达拉奉对大鼠延髓缺血后神经元数量及微血管密度的影响。方法将Wistar大鼠分为假手术组、实验组、缺血对照组。其中实验组及缺血对照组分别给予依达拉奉和生理盐水腹腔注射。标本采用单宁酸氯化铁染色、尼氏染色、Tunel染色,对延髓内微血管密度、神经元及凋亡、神经元计数进行观察。结果实验组中神经元、微血管密度(MVD)减少的程度及神经元凋亡数量均低于缺血对照组。结论依达拉奉在大鼠延髓缺血后具有明显保护作用。  相似文献   

11.
Silver-impregnated retinal preparations were used to study the distribution density and topographic features of small and large ganglionic cells (GC) of Rana ridibunda and Rana temporaria. For both species the increased density of GC (a streak) stretched higher than the naso-temporal axis passing through the optic disk. Beyond the streak the density of small GC was maximal in the central zone of the retina and decreased towards its periphery. For the upper quadrants of the retina the density of small GC was higher than that for the lower ones by 26% on the average. On the contrary, the density of large GC was higher in the lower part of the retina as compared to the upper one, the difference being more pronounced for R. temporaria. The density of large GC was also asymmetric with respect to the dorso-ventral axis being higher in nasal quadrants than in temporal ones by 40-55%. The highest density of large GC was found in the middle zone of the retina. The found structural asymmetry in the retinal output raster may bear an adaptively ecological meaning and may condition the particularities of the formation of the visually guided prey-catching and avoidance reactions.  相似文献   

12.
Electrical coupling between horizontal cells of the turtle retina was investigated by means of two microelectrodes (current and recording ones) penetrating neighbouring cells at a fixed distance from each other. The morphological coupling was revealed by means of fluorescent dye Lucifer Yellow. The electrical coupling was confirmed between elements of similar type (L1--axonal terminals, or L2--cell bodies, or R/G type cells) and no coupling was found between elements of different types, though L1 and L2 are directly connected through thin axons. In the L1 syncytium the electrical coupling at small (less than or equal to 50 microns) but fixed distances between microelectrodes could differ several times depending on the minimal displacement of microelectrodes. This local nonuniformity of coupling can be explained on the basis of structural nonuniformities in the L1 (axon terminal) network. It is unlikely however that the structural nonuniformities can influence the functional properties of horizontal cell network when the retina is stimulated adequately (by light).  相似文献   

13.
The propagation of the slow wave in the stomach and its role in inducing sweeping peristaltic contractions toward the pylorus, essential for a proper digestion and emptying, have been studied for many years. Irregularities in the timing or in the pattern of propagation of the slow wave have been known to induce various gastric malfunctions and, recently, several types of gastric dysrhythmias have been described which could lead to gastric contraction abnormalities. In this study, Du et al. have analyzed the disturbances caused by a simple transmural incision in a human stomach, performed to obtain a biopsy of the muscle, on the propagation pattern of the slow wave. In addition, they show that such an incision may by itself also induce new types of gastric dysrhythmias. These results are important in demonstrating that the function of the stomach can easily be disturbed by such procedures. This mini‐review describes several ways in which inhomogeneities in propagation may affect the conduction pattern of the slow wave, including the genesis of several dysrhythmias, and what is currently known about their impact on gastric contraction and digestion.  相似文献   

14.
The formation of the cerebellum was studied during the first 6 months of the tadpole stage of the bullfrog by using standard histological methods and reconstructions from serial horizontal sections. Three major developmental phases were noted in the formation of the cerebellum. (1) During the first 5 weeks of development, the neuroepithelium proliferated and the dorsal mesencephalic plates increased in size. (2) Starting in the sixth week, a patch of neuroepithelium began to differentiate and gave rise to a small population of Purkinje cells. In subsequent weeks, the area of differentiation continued to spread and a Purkinje cell layer became established along the dorsal margin of the cerebellar plate. (3) In the 12th week, the ventrolateral part of the cerebellar plate began to increase in size and generate two populations of small cells. The lateralmost part of the neuroepithelium in this area generated a group of cells that formed an external granular layer that was one cell deep. Cells of this external granular layer migrated inward into the primitive molecular layer, and by the 26th week only a remnant of an external granular layer remained in the cerebellum. The more medially situated part of the neuroepithelium gave rise to another population of small cells that formed a column, which appeared to be continuous with the Purkinje cells, but differed from them in size. It should be noted that full maturation of the cerebellum occurs during metamorphosis, which in this species remains some 2 years away.  相似文献   

15.
16.
The substantia nigra pars reticulata (SNpr) is a critical site for the control of epileptic seizures. Potentiation of the inhibitory GABAergic input from the striatum to the SNpr suppresses primary or secondary generalized seizures in the rat. The purpose of this study was to examine the possible involvement of the excitatory glutamatergic input from the subthalamic nucleus to the SNpr in the control of both the electroencephalographic and the motor components of amygdala-kindled seizures in the rat. Microinjections of either an N-methyl- -aspartate (NMDA) antagonist in the substantia nigra or a GABAA agonist in the subthalamic nucleus, significantly reduced motor seizures but did not modified the afterdischarges. These results provide evidence for the involvement of the subthalamo-nigral projection in the modulation and the propagation of the motor components of amygdala-kindled seizures.  相似文献   

17.
18.
Tritiated thymidine autoradiography was used to analyze the site, time of origin, and developmental gradients of the specialized lining of the ependymal surface of the third ventricle. Cells destined to form the ependyma are generated between days 15 and 22 of embryogenesis (gestation: 30 +/- 2 days), the majority of the cells undergoing final division on the 18th day of gestation. Ependymal cells originate in an orderly fashion according to 3 gradients. Two gradients of opposite direction (ventrodorsal and dorsoventral) are found in the parasaggital plane. Both gradients start at the level of the hypothalamic sulcus, progressively departing from this anatomical landmark as histogenesis progresses. A third gradient occurs in the caudorostral axis, such that cells located in caudal regions originate earlier than those located in rostral sectors. Thus, an orderly relationship exists between the time of origin of ependymal cells and their final location within the lining of the ventricular wall. These findings indicate, once again, the topographic nature of the gradients of histogenesis. The histogenic gradients displayed by the ependymal lining of the third ventricle appear strongly related to those exhibited by other diencephalic derivatives. The latter suggests that common factors govern the developmental sequence of all diencephalic derivatives as a function of their relative topographic location, independently of their functional role in the adult.  相似文献   

19.
The epidemic of AIDS has been increasingly recognized as a major health and socioeconomic problem, not only in the United States or Africa, but also the rest of the world. The face of the epidemic has changed. The role that mental health providers play has also significantly grown as the epidemic continues on. Prior to the introduction of Highly Active Anti-Retroviral Therapy (HAART) and other advances in HIV care, the patients faced issues that related to death and dying. These advances brought with them renewed hope and resurrected lives. The patients fought with issues related to living new lives with HIV no longer an imminent death threat. In the third decade of AIDS, the struggles of the post-HAART era continue but bring with it more challenges. Mental health providers need to familiarize themselves with these issues so that they can better help HIV patients cope with this devastating disease.  相似文献   

20.
Habituation-like decrements in extracellular measures of synaptic activation (population EPSP) and cell discharge (population spike) were analyzed in the dentate gyrus of the rat following repetitive low-frequency stimulation of the medial and lateral entorhinal cortex. Stimulation of either subdivision of the entorhinal projection system resulted in comparable habituation-like response decrements with similar stimulation regimens. However, habituating stimulation of one subdivision did not result in decreased responsiveness to stimulation of the other. Repetitive low-frequency stimulation or even a single pulse delivered to either subdivision did, however, result in a potentiation of granule cell discharge in response to stimulation of the other subdivision (a form of heterosynaptic potentiation). This heterosynaptic potentiation of granule cell discharge was not accompanied by any increase in the extracellular EPSP. Comparisons of the relationship between the population EPSP and population spike before and during habituating stimulation revealed changes in cell discharge in response to the habituating stimulus which could not be accounted for by changes in synaptic activation alone. The results suggest that repetitive activation of the temporodentate pathway alters granule cell output as a result of two processes, a habituation-like decrement in synaptic activation, and a potentiation of granule cell discharge as a consequence of prior activation.  相似文献   

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