视神经损伤引起斑马鱼视网膜神经细胞凋亡的研究

Studies on the Apoptosis of Retinal Neurons Following Optic Nerve Injure in Zebra fish (Brachydanio rerio)

用石蜡连续切片苏木精染色法 ,通过定量分析研究夹伤和切断视神经后 ,斑马鱼视网膜神经节细胞、视杆和视锥细胞密度的变化 .结果发现 ,在损伤视神经 7～ 2 1 d后 ,上述 3种细胞的细胞核密度均呈减少趋势 ,节细胞减少的比率大于感光细胞 ,而感光细胞中视锥细胞所受影响比视杆细胞更为明显 ;在夹伤和切断视神经两种情况中 ,后者引起视网膜神经节细胞核密度的减少更为显著 .上述结果表明 ,损伤视神经不但影响与其相连的神经节细胞 ,而且可逆向跨神经元地影响感光细胞的变化 .由上述结果推测 ,由于损伤视神经使视网膜神经节细胞失去靶组织而引起的各种神经细胞密度减少是视网膜中神经细胞凋亡的表现 .

The changes of the density of retinal ganglion cells, rod cells and cone cells of Zebra fish following optic nerve crush or section were quantitatively studied with paraffin continuous sections stained by hematxylin.The results showed that the density of nucleus of the three-type retinal neurons was decreased during 7~21 days after optic nerve injure.The decreased ratio of the GCs was bigger than that of photoreceptors (including CCs and RCs), especially in CCs.In both the crush and section conditioning , the change of optic nerves was more obvious in the latter (section condition).These changes indicated that optic nerve injure could not only affect the retinal ganglion cells directly, but could transneuronally affect the changes of photoreceptors. It can be supposed from all the results above that the decrease of the density of retinal neurons may be due to the loss of their target tissues. It is an expression of apoptosis of retinal neurons.