大鼠黑质Orexin的电生理效应及其与帕金森病关系的实验研究

发布时间：2018-04-08 21:01

本文选题：Orexin　切入点：黑质致密带　出处：《青岛大学》2014年硕士论文

【摘要】：黑质是基底神经节的重要核团之一,在机体运动功能调节中发挥重要作用。Orexin是下丘脑神经肽家族成员,可直接参与调节中枢运动功能。形态学研究证实,黑质接受大量来自下丘脑的orexin能纤维支配,并表达高水平的orexin1和orexin2(OX1和OX2)受体。帕金森病晚期患者下丘脑orexin能神经元缺失,脑脊液orexin水平降低,且orexin的水平与帕金森病严重程度呈负相关。目的：本实验探究orexin-A和OX1受体阻断剂SB-334867对正常和6-羟基多巴胺(6-hydroxydopamine,6-OHDA)帕金森病模型大鼠黑质神经元电活动的调节,以及正常和帕金森病大鼠黑质OX1受体的表达。方法：本实验采用多管微电极在体细胞外电生理记录、6-OHDA帕金森病模型大鼠的制备、核团埋管术以及免疫组织化学染色等实验方法。结果：1.正常大鼠黑质致密带微压力注射0.01mM的orexin-A,在记录到的58个多巴胺能神经元中,有36个(62.1%)放电频率明显升高,自发放电频率由2.3±0.3Hz升高至4.2±0.5Hz,平均升高101.0±18.0%(P0.001)。在正常大鼠黑质网状带共记录到54个GABA能神经元,微压力注射orexin-A可使其中24个(44.4%)神经元放电频率明显升高,自发放电频率由24.2±2.0Hz升高至31.4±2.7Hz,平均升高31.3±5.3%(P0.001)。2.在正常大鼠黑质致密带微压力注射0.1mM的SB-334867,在记录到的30个多巴胺能神经元中,有19个(63.3%)放电频率明显降低,自发放电频率由3.1±0.5Hz降低至1.0±0.3Hz,平均降低66.3±6.7%(P0.001);在黑质网状带记录到的21个GABA能神经元中,SB-334767可使其中10个(47.6%)神经元放电频率明显降低,自发放电频率由21.9±3.0Hz降低至16.2±3.4Hz,平均降低28.44±7.9%(P0.01)。3在6-OHDA帕金森病模型大鼠损毁侧,微压力注射0.01mM的orexin-A,可使黑质致密带记录到的21个多巴胺能神经元中的12个(57.1%)放电频率明显升高,由4.1±0.6Hz升高到6.5±1.0Hz,平均升高58.2±11.8%(P0.01)。在记录到的12个黑质网状带GABA能神经元中,orexin-A可使其中7个(58.3%)神经元放电频率明显升高,由19.6±2.7Hz升高到23.5±3.8Hz,平均升高18.8±3.0%(P0.05)。在正常和6-OHDA帕金森病模型大鼠,orexin-A对黑质致密带多巴胺能神经元的兴奋效应较黑质网状带强(正常大鼠P0.01；帕金森病模型大鼠P0.05)。4.免疫组织化学染色显示,正常及帕金森病模型大鼠黑质均表达OX1受体。结论：Orexin-A可提高黑质致密带多巴胺能神经元和网状带GABA能神经元兴奋性。内源性OX1受体参与调节黑质致密带多巴胺能神经元和网状带GABA能神经元兴奋性。在帕金森病模型大鼠,orexin-A也可使黑质致密带多巴胺能神经元和网状带GABA能神经元兴奋性升高。正常及帕金森病模型大鼠黑质均表达OX1受体。本实验结果为深入探讨黑质orexin-A在帕金森病发病中的作用提供了一定的理论和实验依据。
[Abstract]:Substantia nigra is one of the most important nuclei in basal ganglia and plays an important role in the regulation of motor function.Morphological studies demonstrated that the substantia nigra was innervated by a large number of orexin energy fibers from the hypothalamus and expressed high levels of orexin1 and orexin2(OX1 and OX2) receptors.Orexin neurons were absent in hypothalamus and orexin level in cerebrospinal fluid was decreased in patients with advanced Parkinson's disease. The level of orexin was negatively correlated with the severity of Parkinson's disease.Aim: to investigate the effects of orexin-A and OX1 receptor blocker SB-334867 on the electrical activity of substantia nigra neurons in normal and 6-hydroxydopamine 6-hydroxydopamine 6-OHDA-Parkinson disease rats and the expression of OX1 receptors in the substantia nigra of normal and Parkinson's disease rats.Methods: the preparation of 6-OHDA Parkinson's disease model rats with multi-tube microelectrode in vitro electrophysiological recording, the implantation of nuclear tube and immunohistochemical staining were used in this experiment.The result is 1: 1.Of the 58 dopaminergic neurons recorded, 36 of the 58 dopaminergic neurons in the normal substantia nigra were injected with orexin-A under micropressure. The spontaneous discharge frequency increased from 2.3 卤0.3Hz to 4.2 卤0.5Hz.A total of 54 GABA neurons were recorded in the substantia nigra reticularis in normal rats. The frequency of spontaneous discharge increased from 24.2 卤2.0Hz to 31.4 卤2.7Hz. the frequency of spontaneous discharge increased from 24.2 卤2.0Hz to 31.4 卤2.7Hz.In normal rat substantia nigra, the discharge frequency of SB-334867 was significantly decreased in 19 of 30 dopaminergic neurons recorded by micropressure injection of 0.1mM.The frequency of spontaneous discharge decreased from 3.1 卤0.5Hz to 1.0 卤0.3 Hz, and decreased by 66.3 卤6.7 Hz on average, and SB-334767 significantly decreased the firing frequency of 10 neurons among 21 GABA neurons recorded in the substantia nigra reticularis.The frequency of spontaneous discharge decreased from 21.9 卤3.0Hz to 16.2 卤3.4 Hz, and decreased by 28.44 卤7.9%(P0.01).3 on the lesion side of 6-OHDA Parkinson's disease model rats. Injection of 0.01mM orexin-A under micropressure could significantly increase the discharge frequency of 12 dopaminergic neurons recorded in the substantia nigra compact band (12 of 21 dopaminergic neurons recorded in the substantia nigra compact band).From 4.1 卤0.6Hz to 6.5 卤1.0Hz, the average increase was 58.2 卤11.8hz.Among the 12 GABA neurons recorded in the substantia nigra reticularis nigra, the firing frequency of 7 neurons was significantly increased from 19.6 卤2.7Hz to 23.5 卤3.8 Hz, and the average increase was 18.8 卤3.0 Hz.In normal and 6-OHDA Parkinson's disease model rats, the excitatory effect of lorexin-A on the dopaminergic neurons in the substantia nigra compacta is stronger than that in the substantia nigra reticularis (P0.01 in normal rats and P0.05. 4 in Parkinson's disease model rats).Immunohistochemical staining showed that OX1 receptors were expressed in the substantia nigra of normal and Parkinson's disease rats.Conclusion: Orexin-A can increase the excitability of dopaminergic neurons in substantia nigra and GABA neurons in reticular zone.Endogenous OX1 receptors are involved in the regulation of excitability of dopaminergic neurons in the substantia nigra compact zone and GABA neurons in the reticular zone.In Parkinson's disease model rats, moorexin-A also increased the excitability of dopaminergic neurons in the substantia nigra compact zone and GABA neurons in the reticular zone of the substantia nigra.Both normal and Parkinson's disease model rats expressed OX1 receptors in substantia nigra.The results provide a theoretical and experimental basis for the further study of the role of substantia nigra orexin-A in the pathogenesis of Parkinson's disease.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R742.5

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