形觉剥夺性弱视幼猫视皮质17区GAP-43的表达

发布时间：2018-04-04 21:55

本文选题：形觉剥夺　切入点：弱视　出处：《昆明医学院》2010年硕士论文

【摘要】： 研究目的本研究的目的主要是观察形觉剥夺性弱视动物模型及对它们应用左旋多巴治疗后,视皮质17区生长相关蛋白GAP-43的表达,从而探讨形觉剥夺性弱视形成的可能机制及左旋多巴对形觉剥夺性弱视视觉功能恢复作用的可能机制。研究方法 50只4周龄幼猫,随机分为正常组、剥夺组、对照组、低剂量组及高剂量组共5组,每组10只。后四组于4周龄时行左眼睑缝合术,8周龄时经PVEP检测确定为弱视形成后:剥夺组处死所有动物;对照组打开眼睑反向缝合右眼睑4周做遮盖治疗模型;低剂量组与高剂量组打开眼睑分别予以20mg/kg、80mg/kg左旋多巴溶液灌胃给药,每日一次,持续4周,行PVEP检测后处死动物。正常组于8周龄时行PVEP检测后随机处死5只,剩余5只于12周龄时行PVEP检测后处死。所有动物处死后取右脑半球视皮质17区行HE及免疫组织化学染色观察GAP-43蛋白免疫阳性细胞数。研究结果 (1)电生理结果:PVEP主要以P_(100)波振幅及潜时改变为特点。8周龄时,剥夺组、低剂量组、高剂量剥夺眼P_(100)波振幅比对侧眼及同周龄正常组幅值降低,潜时延长(P＜0.05);12周龄时,低剂量组剥夺眼P_(100)波振幅增高,与对侧眼及同周龄正常组相比无差异(P＞0.05),而P_(100)波潜时则未达到正常(P＜0.05);高剂量组剥夺眼P_(100)波振幅增高、潜时缩短,与对侧眼及同周龄正常组相比无差异(P＞0.05)。 (2)光镜下,HE染色结果显示:剥夺组视皮质神经元的数目有所减少,形态不规则,体积大小不一,胞浆突起变短或消失,有些胞核变小、变暗。应用左旋多巴后,高剂量组神经元大部分恢复,细胞体积增大,轴突也有一定程度的恢复;对照组、低剂量组都仅有少数的神经元有恢复。 (3)免疫组化结果:剥夺组较正常组GAP-43表达明显减少,差异有显著性(P＜0.05);高剂量组GAP-43表达与正常组基本相似,差异无显著性(P＞0.05);对照组、低剂量组和正常组相比有显著性差异(P＜0.05)。结论 (1)剥夺组较正常组视皮质17区GAP-43表达明显减少,提示GAP-43可能在形觉剥夺性弱视形成过程中起一定的作用。 (2)应用左旋多巴干预后视皮质17区GAP-43表达增多,提示左旋多巴对形觉剥夺性弱视视功能改善的机制可能是通过GAP-43表达的改变而实现的。
[Abstract]:Research purposeThe aim of this study was to observe the expression of growth-associated protein GAP-43 in the 17 region of the visual cortex after treatment with L-dopa in a form-deprived amblyopia animal model.The possible mechanism of formation of form-deprived amblyopia and the possible mechanism of the effect of levodopa on the recovery of visual function of form-deprived amblyopia were discussed.Research methodFifty 4-week-old kittens were randomly divided into normal group, deprivation group, control group, low dose group and high dose group with 10 cats in each group.After the left eyelid suture was performed at the age of 4 weeks, the left eyelid suture was confirmed as amblyopia by PVEP test: all the animals were killed in the deprivation group, the right eyelid was sutured in the control group for 4 weeks, and the model of covering treatment was made after opening the eyelid and suturing the right eyelid for 4 weeks.Open eyelids of low dose group and high dose group were given 20 mg / kg 80 mg / kg levodopa solution intragastrically, once a day for 4 weeks. The animals were killed after PVEP test.In the normal group, 5 rats were killed randomly after PVEP at 8 weeks old, and the remaining 5 rats were killed after PVEP test at 12 weeks old.All the animals were killed and the number of GAP-43 immunoreactive cells was observed by HE and immunohistochemical staining in 17 areas of the visual cortex of the right hemisphere.Research results(1) the electrophysiological results of PVEP were mainly characterized by the change of amplitude and latent time of PSP 100) wave. At the age of 8 weeks, the amplitude ratio of the deprivation group, the low dose group and the high dose deprived eye decreased the amplitudes of the lateral eye and the normal group of the same age, and the latent time prolonged at 12 weeks of age (P < 0.05).There was no difference between the contralateral eye and normal group (P > 0.05).(2) the results of HE staining under light microscope showed that the number of neurons in the optic cortex of the deprivation group was decreased, the shape was irregular, the volume was different, the cytoplasmic processes were shortened or disappeared, and some of the nuclei became smaller and darker.After the application of levodopa, the majority of neurons recovered, the cell volume increased, and the axons recovered to a certain extent in the high dose group, and only a few neurons recovered in the control group and the low dose group.3) Immunohistochemical results: the expression of GAP-43 in deprivation group was significantly lower than that in normal group (P < 0.05), the expression of GAP-43 in high dose group was similar to that in normal group (P > 0.05), and in control group, there was significant difference between low dose group and normal group (P < 0.05).Conclusion1) the expression of GAP-43 in the 17 area of visual cortex in deprivation group was significantly lower than that in normal group, suggesting that GAP-43 might play a role in the formation of form deprivation amblyopia.(2) the increase of GAP-43 expression in the 17 region of visual cortex after the intervention of levodopa suggests that the mechanism of levodopa in improving the function of form deprivation amblyopia may be realized by the change of GAP-43 expression.
【学位授予单位】：昆明医学院
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R777.44

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