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mGluR1在单眼形觉剥夺性弱视大鼠视网膜的表达及阳性神经节细胞超微结构观察
Expression of mGluR1 at Retian of Monocular Deprived Amblyopia Rats and the Observation of Retina Ganglion Cell Ultrastructure
【作者】 王晓艳;
【导师】 刘向玲;
【作者基本信息】 新乡医学院 , 眼科学, 2009, 硕士
【摘要】 目的研究视觉形成关键期内单眼形觉剥夺弱视大鼠视网膜中mGluR1的表达规律及神经节细胞超微结构变化,为临床上揭示弱视的病理机制及防治提供理论依据。方法随机对照取同期实验动物,建立大鼠单眼形觉剥夺弱视模型,经图形视觉诱发电位(PVEP)检测证实造模成功后,与正常对照组大鼠一起灌注、固定、取材,所得标本分为实验组未形觉剥夺眼、实验组形觉剥夺眼和正常对照眼组。三组分别做石蜡切片,脱蜡后进行HE染色,免疫组织化学染色,取电镜标本进行观察,摄像显微镜分层照相,计算机图像分析系统进行图像分析,SPSS12.0统计软件进行方差分析。结果①PVEP检测结果:经PVEP检测后可见,与正常组大鼠眼和实验组未形觉剥夺眼PVEP相比,实验组形觉剥夺眼PVEP的P波潜时延长、波幅降低,差异有显著性(P<0.01)。而正常组大鼠眼PVEP和实验组未形觉剥夺眼PVEP相比,差异无显著性(P>0.05)。大鼠单眼形觉剥夺弱视模型造模成功。②HE结果:正常组大鼠眼和实验组未形觉剥夺眼视网膜结构清晰,神经节细胞体积较大。实验组形觉剥夺眼视网膜各层普遍变薄,尤以内核层和内网状丛最为明显,各层细胞排列稀疏,胞体变小,排列稍紊乱。节细胞数量减少。③免疫组织化学结果:实验组形觉剥夺眼视网膜与正常眼视网膜和实验组非形觉剥夺眼视网膜相比mGluR1阳性着色平均光密度和平均灰度值进行统计分析,两者差异有显著性意义(p<0.01)。正常眼视网膜和实验组非形觉剥夺眼视网膜相比mGluR1阳性着色平均光密度和平均灰度值,两者差异无显著性意义(p>0.01)。④电镜观察结果:实验组形觉剥夺眼视网膜可见神经节细胞胞质轻度水肿,线粒体嵴和膜融合或消失,排列紊乱,粗面内质网脱颗粒现象明显。突触小泡明显减少,突触区线粒体肿胀,嵴间腔扩大,嵴紊乱。正常对照组视网膜和实验组非形觉剥夺眼视网膜神经元胞核正常,核膜完整,线粒体嵴规则,高尔基体发达,粗面内质网发达。突触小泡清晰可辨,量多均匀分布。结论①.单眼形觉剥夺弱视大鼠弱视眼视网膜的病理改变説明单眼形觉剥夺的发病机制与视网膜损伤有关。②弱视眼视网膜神经元发生形态改变,可能与视觉神经冲动传入减少致视网膜神经节细胞过早凋亡有关。③形觉剥夺致神经冲动传入减少,视网膜的mGluR1表达减少,突触可塑性变化,致神经元发生萎缩可能是弱视发病机理之一。④.通过对正常及弱视大鼠视网膜神经细胞的超微结构观察,证实了出生后早期不正常的视觉经历(形觉剥夺)可以导致视网膜神经节细胞发生不同程度的组织病理学损害。
【Abstract】 Objective To explore the regulation of expression of mGluR1 and the changes of retinal ganglial cell ultrastructure at retinal of monocular deprivation amblyopia rat within critical period ,in order to reveal the pathology mechanism of amblyopia and provide the theory of prevention and cure.Methods Establishing the model of monocular deprivation amblyopia rat. After proving the model successful by PVEP, all of the rats were randomly divided into three groups: normal group,undeprived eyes of experimental group and deprived eyes of experimental group. HE staining after dewaxinngn, then immunohistochemistry, electron microscope, photography microscope, computer image analysis, SPSS 11.5 and ANOV were used to get the results.Results①Results of PVEP demonstrated that contrasted to undeprived eyes of experimental group rats and normal eyes, P wave of deprived eyes were prolonged in potential time and were lowed in amplitude. The difference was significant (P<0.01). However, there was no significant difference between normal eyes and undeprived eyes of experimental group rats(P>0.05). The monocular deprived amblyopia models of rat were built successfully.②Results of HE : The density of cells in the retinal ganglion cell layer and the thickness of every layer in retinal which were undeprived eyes of experimental group rats and normal eyes were regularity. The cubia capacity of retinal ganglion cells were large.The thickness of every layer in retinal which were deprived eyes of experimental group became thinning .The cell body became shrink and arranged disord.There is no evident differentiation be found between normal eyes and undeprived eyes of experimental group rats.③Compared with undeprived eyes of experimental groupd and normal group , the area of immunopositive neurons in deprived eyes of experimental groupare deficiency .There is significant difference between them (P<0.01). there was no significant difference between normal eyes and undeprived eyes of experimental group rats(P>0.01)④We can see some neurons’kytoplasm edema slightly, mitochondrial cristae and membrane fused or disappeared, arrangement confused, rough endoplasmic reticulum degranulation obvious, nuclear membrane crimple in the deprived eyes of experimental group. For normal eyes and undeprived eyes of experimental group, the nucleis of neurons are normal, karyolemma integrity, mitochondria cristae regulation, Glogi’s body and rough endoplasmic reticulum developed. Syanptic cesicles can be identified clearly , uniformly distributed . Conclusion①The retina of monocular deprivation amblyopia has been damaged .②There are morphological abnormals happened in retinal ganglial cell of monocular derivation amblyopia .③Reduced afference of nerve pulse because of monocular deprivation leads to the expression difficiency of mGluR1 in retinal ganglial cell, then synaptic plasticity happened , then neurons atrophy occurred may be one of the etiopathogenesis of amblyopia .④Normal and visually-impaired by retina ganglial cell ultrastructure observation of normal visual and deprived eyes of experimental group, Confirmed the off-normal vision experience(shape sense deprives) of early birth may cause the retina ganglion cell to have the varying degree organization pathology harm.
【Key words】 monocular deprivation amblyopia; mGluR1; retina; visual cortex; Synaptic plasticity;