小鼠出生前后角膜神经分布的变化

Changes of corneal innervation before and after birth in mice

目的了解小鼠出生前后角膜神经纤维密度与总长度的变化。方法 20只C57/BL6小鼠根据出生前后不同时期分为4组,分别为胚胎期17d(E17d)组、胚胎期20d(E20d)组、出生当天(P0d)组、出生后3d(P3d)组,每组5只鼠10只角膜。采用β-微管蛋白Ⅲ抗体对不同组别的小鼠角膜进行整铺片免疫荧光染色。使用荧光显微镜显示各年龄组的角膜神经分布;使用DeltaVisionCore拍摄角膜背鼻侧、背颞侧、腹鼻侧和腹颞侧的神经纤维图像,分别计算并比较不同组别小鼠的角膜表面积、角膜神经纤维密度与总长度以及角膜各分区的神经纤维密度。结果 E17d组、E20d组、P0d组和P3d组小鼠的角膜表面积分别为(0.34±0.03)mm2、(0.39±0.03)mm2、(0.46±0.06)mm2和(0.51±0.01)mm2,角膜表面积随年龄的增长而逐渐增大,但是相邻年龄组间差异均无统计学意义(均为P>0.05)。E17d组、E20d组、P0d组和P3d组的角膜神经纤维密度分别为(9.11±0.65)mm·mm-2、(13.04±1.83)mm·mm-2、(9.02±0.45)mm·mm-2和(12.87±1.04)mm·mm-2;E17d组、E20d组、P0d组和P3d组的角膜神经纤维总长度分别为(3.10±0.59)mm、(5.09±1.03)mm、(4.15±0.46)mm和(6.56±1.11)mm。除了E20d组到P0d组,其余相邻年龄组间的角膜神经纤维密度和总长度都随年龄的增长而增加(P<0.05)。角膜4个分区的神经纤维密度变化趋势与整个角膜的神经纤维密度变化趋势一致。结论小鼠出生前后角膜神经纤维有变化,出生当天小鼠的角膜神经纤维密度与总长度低于出生前,随后出现追赶性增长。

Objeetive To investigate the changes in the density and total length of corneal nerve fibers before and after birth in mice. Methods Twenty C57/BL5 mice were divided into four groups according to the age before and after birth： embryo- nal 17 days group （E17 d group）, embryonal 20 days group （E20 d group）, postnatal 0 day group （ P0 d group） and postnatal 3 days group （ P3 d group）, 5 cases in each group. The whole-mount corneas in all groups were immunostained by anti-neuron-spe- cific β-Ⅲ tubulin antibody. Corneal innervation in each age group was showed by fluo- rescence microscope, and DeltaVision Core was used to capture the nerve fiber images in corneal four quadrants： dorsal-nasal region, dorsal-temporal, ventral-nasal region, ventral-temporal. And then mouse corneal surface area, densities and total length of nerve fibers in whole cornea or four regions were calculated, respectively. Results The corneal surface area in El7 d group, E20 d group, P0 d group and P3 d group were （0.34 ±0. 03）mm2, （0.39 ±0.03） mm^2, （0, 46 ±0.06） mm^2 and （0.51 ±0. 01 ） mm^2, which increased gradually with the age increased, but there was no statistical difference between each two adjacent group （ both P 〉 0.05 ）. The densities of corneal nerve fibers in El7 d group, E20 d group, P0 d group and P3 d group were （9. 11±0. 65）mm · mm ^-2, （13. 04 ±1. 83 ） mm · mm ^-2, （9.02±0.45）mm · mm ^-2： and （12.87±1.04）mm · mm ^-2, respectively; The total lengths of corneal nerve fibers in El7 d group, E20 d group, P0 d group and P3 d group were （3. 10 ±0. 59）mm, （5.09 ±1.03）nun, （4.15 ± 0.46） nun and （ 6.56 ± 1.11 ） nun, respectively. Except for E20 d group and P0 d group, the density and total length of corneal nerve fibers between other two adjacent age groups significantly increased with the age increased （P 〈 0.05 ）. The changes of nerve fiber densities in corneal four regions were similar with that in whole cornea. Conclusion The development of nerve fibers in whole cornea is changed before and after birth in mice. The density and total length of corneal nerve fibers at the day of birth are lower than those before birth, which catch-up increase subsequently with the time prolongs.