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1.
目的观察不同神经营养因子对体外培养中脑多巴胺能神经元(DN)存活和分化的作用。方法选取14d孕鼠,无菌条件下取出胎鼠,采用酶消化法培养中脑DN神经元,在培养过程中,分别加入不同浓度的胶质细胞源性神经营养因子(GDNF)、神经营养因子3(NT3)、脑源性神经营养因子(BDNF)和神经生长因子(NGF),通过细胞形态学和免疫荧光方法进行细胞纯度鉴定,观察不同作用条件下TH阳性细胞率确定细胞存活。结果以10~60ng/L的GDNF或BDNF持续培养10d,中脑多巴胺能神经元的存活率明显高于NGF和NT3作用组,浓度为20ng/m l的GDNF作用最强,能够维持60%的DN神经元存活。此外BDNF和GDNF能够增加DN神经元的数目,但未发现明显的剂量依赖效应,当GDNF与BDNF联合应用时,未见DN神经元的保护作用增强。结论GDNF和BDNF对原代培养的多巴胺能神经元存活具有较强的促进作用,并能诱导神经前体细胞分化为DN神经元。  相似文献
2.
Early diagnosis of Parkinson's disease (PD) is required to improve therapeutic responses. Indeed, a clinical diagnosis of resting tremor, rigidity, movement and postural deficiencies usually reflect >50% loss of the nigrostriatal system in disease. In a step to address this, quantitative diffusion tensor magnetic resonance imaging (DTI) was used to assess nigrostriatal degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication model of dopaminergic nigral degeneration. We now demonstrate increased average diffusion (p<0.005) and decreased fractional anisotropy (p<0.03) in the substantia nigra (SN) of 5- to 7-day MPTP-treated animals when compared to saline controls. Transverse diffusivity demonstrated the most significant differences (p < or = 0.002) and correlated with the numbers of SN dopaminergic neurons (r=-0.75, p=0.012). No differences were found in the striatum, corpus callosum, cerebral cortex, or ventricles. These results demonstrate that DTI may be used as a surrogate biomarker of nigral dopaminergic neuronal degeneration.  相似文献
3.
人骨髓间充质干细胞向多巴胺神经元分化的体外研究   总被引:2,自引:0,他引:2  
目的探讨人骨髓间充质干细胞(hMSC)向神经元和多巴胺神经元分化的潜能。方法分离和纯化hMSCs;在体外以WHI-P131预处理和碱性成纤维细胞生长因子预诱导后,全反式维甲酸和胶质细胞源性神经营养因子联合诱导hMSCs向神经元和多巴胺神经元分化。光镜下观察其分化过程中hMSCs的形态变化,免疫组化检测诱导前后细胞是否表达神经元和多巴胺能神经元标志蛋白。结果诱导后的hMSCs能分化成为具有典型神经元形态的细胞,并明显表达抗人神经巢蛋白(nestin)[(54.2±3.7)%]和神经元特异性烯醇化酶(NSE)[(77.0±5.7)%],低表达胶质纤维酸性蛋白(GFAP)[(8.8±2.4)%];对照组细胞这些表达均为阴性;而且相当部分hMSCs表达酪氨酸羟化酶(TH)[(36.5±15.8)%]和多巴胺转运体(DAT)[(26.0±14.2)%]。结论在适当条件下,hMSCs可分化成为神经元样细胞和多巴胺神经元样细胞。  相似文献
4.
BACKGROUND: Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor (GDNF) injection directly into substantia nigra has relatively greater damages with higher difficulty. GDNF injection into striatum, the target area of dopaminergic neuron, may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport. OBJECTIVE: To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease (PD), and analyze the action pathway. DESIGN: A controlled observation. SETTING: Neurobiological Laboratory of Xuzhou Medical College. MATERIALS: Twenty-four male Kunming mice of 7–8 weeks old were used. GDNF, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were purchased from Sigma Company (USA); LEICAQWin image processing and analytical system. METHODS: The experiments were carried out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006. The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP. The model mice were were randomly divided into four groups with 6 mice in each group: GDNF 4-day group, phosphate buffer solution (PSB) 4-day group, GDNF 6-day group and PSB 6-day group. Mice in the GDNF 4 and 6-day groups were administrated with 1 μL GDNF solution (20 μg/L, dispensed with 0.01 mol/L PBS) injected into right striatum at 4 and 6 days after model establishment. Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points. ② On the 12th day after model establishment, the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides. The positive neurons of tyroxine hydroxylase (TH) and calcium binding protein (CB) with obvious nucleolus and clear outline were randomly selected for the measurement, and the number of positive neurons in unit area was counted. MAIN OUTCOME MEASURES: Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group. RESULTS: All the 24 mice were involved in the analysis of results. The numbers of TH+ and CB+ neurons in the GDNF 4-day group (54.33±6.92, 46.33±5.54) were obviously more than those in the PBS 4-day group (27.67±5.01, 21.50±5.96, P < 0.01). The numbers of TH+ and CB+ neurons in the GDNF 6-day group (75.67±5.39, 69.67±8.69) were obviously more than those in the PBS 6-day group (27.17±4.50, 21.33±5.72, P < 0.01) and those in the GDNF 4-day group (P < 0.01). CONCLUSION: Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice, and it may be related to the increase of CB expression.  相似文献
5.
The response of noradrenergic (NE), serotonergic (5-HT), and dopaminergic (DA), neurons to repeated presentations (once/2 s for 64 trials) of phasic auditory (click) and visual (flash) stimuli was examined in freely moving cats. All 3 groups of neurons displayed similar response latencies and somewhat similar durations of excitation to both stimulus modalities. 5-HT neurons in the mesencephalic raphe nuclei showed no decrease in responsiveness across trials to either of the stimuli. DA neurons in the substantia nigra displayed no decrease in responsiveness across trials to the auditory stimulus, but did display an approximately 50% decrease in response to the visual stimulus. NE neurons in the locus coeruleus showed an approximately 50% decrease in responsiveness to both the auditory and visual stimuli. These data are consistent with previous studies showing that the response of many neurons in the brainstem reticular formation habituates to the repetitive presentation of sensory stimuli. They also show that the response of reticular formation neurons are heterogeneous and that they can be subdivided on the basis of their neurochemical identity. Finally, these data provide support for the involvement of NE neurons, and to a lesser extent DA neurons, in various forms of behavioral plasticity.  相似文献
6.
The present study investigated whether the higher dopaminergic system activation in rats with high (HRs) rather than low (LRs) locomotor activity in response to novelty depend on the number of cells containing the enzyme tyrosine hydroxylase (TH+) and/or differences in the morphology of these cells. One week after the novelty test, brains from male Wistar rats (HRs and LRs) were collected and stained for TH expression (immunohistochemistry) and for morphological analysis (immunofluorescent staining). The morphology and total number of TH+ cells was analyzed for each A9 (substantia nigra) and A10 (ventral tegmental area) group of the midbrain dopaminergic cells. We found that HRs had a higher total number of TH+ cells in the whole midbrain dopaminergic region (A9-A10) and in the A9 group only than LRs. In particular midbrain dopaminergic groups of neurons, HR/LR differences were regionally specific: HRs had a higher total number of TH+ cells in the A9, and in the anterior part of the A10. In contrast, the LRs had a higher number of TH+ cells in the parabrachial pigmented nucleus (A10) and in the posterior part of the A9. There were no significant differences in the morphology of the midbrain dopamine neurons between HRs and LRs. Moreover, there was a positive correlation between the total number of TH+ neurons and the locomotor activity score in response to novelty in the whole A9-A10 region and in the particular A9 group only. The results obtained indicate that the higher behavioral activation in resting conditions correlates with the higher number rather than changes in the morphology of the midbrain dopaminergic TH+ cells. It supports findings on the higher level of dopaminergic system activation in high responders to novelty that depends on the number of midbrain dopaminergic TH+ neurons.  相似文献
7.
目的探讨血管紧张素II(AngiotensinII,AII)诱导神经干细胞(Neural stem cells,NSCs)定向分化为多巴胺(Dopamine,DA)能神经元的过程中血管紧张素1型(AT1)受体和血管紧张素2型(AT2)受体所起的作用。方法在无血清培养基中分离培养NSCs,通过巢蛋白(nestin)免疫细胞化学对神经前体细胞进行鉴定;在此基础上,将第二代的NSCs在含10%胎牛血清的培养基中按照实验设计分为6组,分别是,A:对照组,B:AII组,C:AT1受体拮抗剂ZD7155组,D:AT1受体拮抗剂ZD7155+AII组,E:AT2受体拮抗剂PD123319组,F:AT2受体拮抗剂PD123319+AII组,观察NSCs向DA能神经元定向诱导分化情况。通过酪氨酸羟化酶(TH)免疫细胞化学进行DA能神经元鉴定,并观察各组DA能神经元突触的长度变化,通过实时荧光定量RT-PCR检测各实验组中TH基因表达水平。结果细胞团中可以看到nestin免疫阳性着色,实时荧光定量RT-PCR法检测B组、D组的TH基因表达水平高于对照组,差异有统计学意义(P<0.05),C、E、F组的TH基因表达水平与对照组比较...  相似文献
8.
目的在体外成功分离培养并扩增神经干细胞(NSCs)的基础上,研究外源性血管紧张素Ⅱ(Ang Ⅱ)对NSCs向多巴胺(DA)能神经元分化的影响。方法(1)分离培养新生1d SD大鼠脑组织NSCs,免疫细胞学方法测定NSCs特异性标志物神经上皮干细胞蛋白(Nestin)表达及其分化为神经元、神经胶质细胞的能力;(2)按培养液中Ang Ⅱ的浓度不同,分5个浓度(100、200、400、600、800nmol/L)对第二代NSCs进行诱导分化。10d后采用免疫细胞学方法检测DA能神经元标志物酪氨酸羟化酶(TH)和神经胶质细胞标志物胶质纤维酸性蛋白(GFAP)的表达,半定量RT-PCR(SQ-PCR)测定分化细胞中TH mRNA的相对表达量。结果外源性Ang Ⅱ诱导提高NSCs向TH阳性细胞分化的比率,TH mRNA相对表达量亦增加,以Ang Ⅱ浓度为400nmol/L及600nmol/L的诱导效果最明显,TH阳性细胞率分别为10.77%和11.34%,TH mRNA相对表达量分别为(0.4023±0.0515)和(0.3971±0.0319),两组间比较无统计学意义(P〉0.05);其中400nmol/L Ang Ⅱ组分化细胞中GFAP阳性细胞率高于对照组,有统计学意义(P〈0.05)。结论外源性AngⅡ促进NSCs向DA能神经元分化,在400~600nmol/L浓度范围内AngⅡ的诱导效能更显著;AngⅡ促进NSCs向DA能神经元分化的机制可能与同时促进星型胶质细胞(AS)分化有关。  相似文献
9.
Epidemiological studies have reported that smoking is associated with a lower incidence of Parkinson's disease (PD), leading to theories that smoking in general and nicotine in particular might be neuroprotective. Recent studies suggested cholinergic anti-inflammatory pathway-regulating microglial activation through alpha7 nicotinic receptors. In the present study, we used lipopolysaccharide (LPS)-induced in vitro and in vivo inflammation models to investigate whether nicotine has a protective effect on the dopaminergic system through an anti-inflammatory mechanism. Nicotine pretreatment considerably decreased microglial activation with significant reduction of tumour necrosis factor (TNF)-alpha mRNA expression and TNF-alpha release induced by LPS stimulation. In co-cultures of microglia and mesencephalic neurons, nicotine pretreatment significantly decreased the loss of tyrosine hydroxylase-immunopositive (TH-ip) cells, approximately twice more than the LPS-only treatment. alpha-Bungarotoxin, an alpha7 nicotinic acetylcholine receptor subunit-selective blocker, considerably blocked the inhibitory effects of nicotine on microglial activation and TH-ip neuronal loss. Chronic nicotine pretreatment in rats showed that TH-ip neuronal loss induced by LPS stimulation in the substantia nigra was dramatically decreased, which was clearly accompanied by a reduction in the formation of TNF-alpha. The present study demonstrated that nicotine has a neuroprotective effect on dopaminergic neurons via an anti-inflammatory mechanism mediated by the modulation of microglial activation. Along with various neuroprotective effects of nicotine, the anti-inflammatory mechanism of nicotine could have a major therapeutic implication in the preventive treatment of PD.  相似文献
10.
目的探讨碱性成纤维细胞生长因子(bFGF)预诱导对骨髓基质干细胞(MSCs)向多巴胺(DA)能神经元分化的影响。方法取雄性Wistar大鼠股骨和胫骨骨髓,进行MSCs的体外培养、传代扩增及纯化。bFGF预诱导24h后,依据加入的神经营养因子不同分为单唾液酸四己糖神经节苷脂(GMl)组、胶质源性神经营养因子(GDNF)组和GDNF+GMl组,以及对照组。倒置显微镜下观察细胞形态变化,分别在预诱导第3d、7d进行神经元特异性烯醇化酶(NSE)、神经胶质酸性蛋白(GFAP)、酪氨酸羟化酶(TH)免疫细胞化学检测。计数NSE和TH阳性细胞数,并计算阳性细胞百分比。结果对照组见少量NSE阳性细胞。实验组于诱导第3d、7d见较多数量的NSE、TH阳性细胞,GFAP阴性。bFGF预诱导各组中GDNF+GMl组NSE、TH阳性细胞率最高,GDNF组次之,GMl组最低,组间比较差异有统计学意义(均P〈0.01)。结论bF—GF预诱导不仅可明显促进GDNF、GMl诱导MSCs向神经元样细胞分化,表达神经元细胞标志物——NSE;还可促进MSCs向DA能神经元分化,表达DA能神经元标志物——TH。  相似文献
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