移植视网膜神经元的发育规律及其再生和可塑性意义(英文)

Rule of neuron development in transplanted retina and the significance of its regeneration and plasticity

背景:近年的移植实验表明,移植视网膜内能合成相关的神经活性物质,但移植视网膜内神经活性物质阳性神经元的生长发育情况尚不清楚。目的:观察移植视网膜神经元的分化、发育,神经活性物质的生物合成及其与周围环境、视觉中枢的联系,以探讨神经组织的发育规律及其再生和可塑性。设计:以动物为研究对象,观察对比研究。单位:两所大学的组胚教研室。材料:实验于2002-08/2003-03在广州医学院实验动物中心完成。选择健康SD大鼠96只,雌雄不限。干预:用胚14dSD大鼠视网膜移植至P1大鼠中脑左侧上、下丘间,同时摘除P1鼠右眼,术后第9天移植视网膜的发育时间与生后第1天正常视网膜相当,记为TP1,余类推,应用组织化学方法显示神经元的发育和分化。主要观察指标:移植视网膜和移植视网膜神经元的发育及形态观察。结果:移植视网膜具有正常视网膜的各层结构和相似的生长发育规律,并能合成相关的神经活性物质。移植视网膜内一氧化氮合酶阳性神经元开始出现于TP4,TP12时阳性神经元数量达到高峰,TP22后阳性神经元数目维持在较低的水平。结论:胚胎视网膜脑内移植后能存活且保持原有的生长发育规律,具有正常视网膜一样的组织结构特征。

BACKGROUND:As indicated by transplantation experiments in recent years,correlative neural active substances could be synthesized in the transplanted retina(TP);however,the growth and development situation of neural active substance positive neurons in TP is unclear. OBJECTIVE:To observe the differentiation and development of the neuron, and the biosynthesis of neural active substance in TP and its relationship with environment and visual center to explore the rule of development of nerve tissue and its regeneration and plasticity. DESIGN:An observatory comparative study based on animals. SETTING:Department of histology and embryology of two universities. MATERIALS:The study was conducted in the Experimental Animal Center of Guangzhou Medical College between August 2002 and March 2003.Totally 96 healthy SD rats in either gender were selected. INTERVENTIONS:Embryonal 14 day SD retina was transplanted in between the epithalamus and hypothalamus of the midbrain in P1 rat and the right eye of the P1 rat was removed simultaneously.The development time of TP on the 9th day after operation was corresponding to the normal retina on the 1st day after born,which was then recorded as TP1,and so on.The development and differentiation was shown by histochemical method. MAIN OUTCOME MEASURES:Development and morphological observation of TP and neurons in TP. RESULTS:TP had the same structure of each layer as normal retina and its similar growth and development rule,which also could synthesize relative neural active substance.Nitricoxide synthase(NOS) positive neuron in TP started at TP4 and reached its peak at TP12, but the number of positive neurons was kept on a relative low level after TP22. CONCLUSION:Embryonal retina could survive and remain its original growth and development rule after intracerebral transplantation,which has same structural characters as normal retina.