慢性高眼压大鼠外侧膝状体神经元的损伤

目的观察在持续高眼压状态下大鼠外侧膝状体（lateral geniculate nucleus．LGN）细胞结构的变化及其与视神经纤维丢失的关系。方法通过烧灼大鼠巩膜表层静脉诱导建立大鼠慢性高眼压模型，左眼为实验眼，右眼为对照眼，分别于2、4、6个月后经心脏灌注内固定取材，对两侧LGN及视神经进行形态学观察；通过突触素P38单克隆抗体免疫组化技术，利用计算机图像分析，对LGN视神经末梢突触分布情况进行检测。并对两侧LGN及视神经的观察结果进行比较。结果随高眼压持续时间的延长。大鼠左眼视神经轴突数目以及右侧LGN神经元大小、密度显著减小；LGN内突触素P38免疫反应阳性产物平均光密度值呈下降趋势；LGN神经元的损伤与视神经轴突数目及突触素光密度值显著相关。结论持续性眼压升高对大鼠LGN有明显损伤作用；高眼压大鼠LGN的损伤继发于视神经的损伤。

Changes of neurous in the lateral geniculate nucleus in glaucomatous rats

Objective To investigate neuron degeneration in the lateral geniculate nucleus (LGN) and its relationship with optic nerve loss in the experimental rat model of glaucoma.Methods Chronic intraocular pressure elevation was induced by cauterization of the limbal vessels in the left eye of 15 rats,the right eye served as non-operated control.The heats were fixed by perfusing fixing agent after 2 months,4 months,6 months respectively.Histomorphometric analysis was performed on optic nerve and brain cross-sections.Both experimental side and control opposite side were studied.Change of expression of synaptophysin P38 in LGN was studied by immunohistochemistry and estimated by computer image analysis techniques.Results The mean number of neurous in right LGN significantly decreased compared with control side.The values of optic density of P38 immuno-reactivity in the right LGN were significantly lower than that in the left side.Differences in neuron count between control and experimental sides of LGN showed strong association with differences in optic nerve fibers count and synaptic density.Conclusion The present results suggest that significant loss of neurons occurs in LGN of the experimental glaucomatous rat model,which may result from the loss of optic nerve fibers.