小鼠视网膜胆碱能无长突细胞阵列分布及发育过程中的变化

Spatial distribution of mouse retinal cholinergic amacrine cell its changes in different postnatal development

目的本研究分析了小鼠视网膜胆碱能无长突细胞空间分布的规律,并观察了出生后视网膜的生长对其规律性的影响。方法我们用免疫组织化学方法标记不同发育期(P8、P13和成年)的小鼠视网膜神经节细胞层(ganglion cell layer,GCL)及内核层(inner nuclear layer,INL)胆碱能无长突细胞的胞体,用Voronoi domain来量化分析胆碱能阵列的空间分布规律,并使用规则指数RI评价规则度。结果小鼠胆碱能阵列的规则指数RI(5.27)明显高于随机点的规则指数(2.05),这种高规则性在成年小鼠视网膜不同离心度保持高度的一致性,离心度0.25、0.50、0.75、≈1.00时规则指数分别为:INL:4.87±0.67、4.77±0.83、4.31±0.68、4.66±1.38;GCL:2.52±0.83、3.53±0.26、3.70±0.83、3.43±0.43。INL Voronoi domain的面积随离心度增加而扩大,各离心度面积分别为:(650.89±134.00)μm2、(747.23±157.00)μm2、(946.39±220.00)μm2、(1141.79±245.00)μm2。GCL各离心度面积分别为:(875.36±258.00)μm2、(838.07±211.00)μm2、(915.60±256.00)μm2、(1155.40±371.00)μm2,GCL的Voronoi domain的面积在0.25、0.50离心度时差异无统计学意义(P>0.05),但在余离心度时面积随离心度增加而扩大。而在P8、P13和成年三个不同发育阶段,胆碱能阵列的规则指数RI分别为:INL:5.5±0.7、4.7±0.5、4.6±0.9;GCL:4.9±1.2、4.1±0.7、4.2±0.7;P8INL高于P13和成年时(均为P<0.05),而GCL各年龄段差异均无统计学意义(均为P>0.05)。结论视网膜胆碱能阵列的空间分布有非常高的规则性,且这种规则性在出生后早期就形成,而在发育过程中虽然视网膜在扩张,但其规则性并不发生改变。

Objective To analyze the spatial distribution of the mouse cholinergic amacrine cell,and observe the effect of retinal growth on its regularity during postnatal development.Methods Cell body of mouse retinal cholinergic amacrine cells in ganglion cell layer（GCL） and inner nuclear layer（INL） were detected by immunohistochemical method in different postnatal days（P8,P13,adult）.Voronoi domain was used to quantitatively analyze the spatial distribution of the mouse cholinergic mosaics.Regularity index（RI） was selected as an indicator of regularity of cholinergic mosaics in different developmental stages.Results RI of mouse cholinergic amacrine cells was 5.27,much higher than 2.05 of random counterpart,and has a high degree of consensus at different eccentricities,RI at eccentricities with 0.25,0.50,0.75,approximately equal to 1.00 were INL 4.87±0.67,4.77±0.83,4.31±0.68,4.66±1.38;GCL 2.52±0.83,3.53±0.26,3.70±0.83,3.43±0.43,respectively.The voronoi domain area of INL expanded with the eccentricities increased,the areas at each eccentricity were（650.89±134.00）μm2,（747.23±157.00）μm2,（946.39±220.00）μm2,（1 141.79±245.00）μm2,respectively,GCL were（875.36±258.00）μm2,（838.07±211.00）μm2,（915.60±256.00）μm2,（1 155.40±371.00）μm2,respectively.There was no statistical difference in voronoi domain area of GCL between eccentricities with 0.25 and 0.50（P0.05）,but other expanded with the eccentricities increased.RI also has a high degree of consensus in each postnatal stages（RI at different postnatal days：INL 5.5±0.7,4.7±0.5,4.6±0.9;GCL 4.9±1.2,4.1±0.7,4.2±0.7）,RI of INL at P8 was higher than that at P13 and adult（all P0.05）,but there was no statistical difference in RI of GCL between different postnatal days（all P0.05）.Conclusion Retinal cholinergic mosaics have a high degree of regularity which form in very early postnatal stage,then dynamically preserve their regularity when the retina expands.