小鼠视觉发育关键期外侧膝状体胰岛素样生长因子2的动态表达

Dynamic expression of insulin-like growth factor 2 during critical period of visual development in lateral geniculate body of mice

目的探讨视觉发育关键期外侧膝状体(LGB)胰岛素样生长因子2(IGF2)的动态表达变化。方法选取3组不同年龄段的昆明小鼠进行试验,分别为3周龄组,5周龄组,7周龄组,每组12只。采用前爪触地反射实验检测各组小鼠的视觉功能是否正常;采用免疫组织化学技术检测小鼠出生后3、5和7周外侧膝状体IGF2蛋白及其受体的表达水平,分析IGF2蛋白在LGB各局部及其受体的表达变化模式。结果3~7周的发育过程中,在小鼠LGB背侧核IGF2蛋白表达5周时显著减少,7周时显著增加,腹侧核IGF2蛋白表达随时间逐渐增加。LGB背侧核及腹侧核IGF2受体蛋白表达5周时显著增加,7周时减少至3周时水平。结论视觉发育关键期小鼠外侧膝状体IGF2及其受体的表达存在随时间的动态改变,且各局部的表达模式不完全一致,IGF2及其受体可能与小鼠视觉发育可塑性有关。

Objective To detect the dynamic expression of insulin-like growth factor 2(IGF2)in lateral geniculate body(LGB)during the critical period of visual development.Methods Three groups of Kunming mice of different ages were selected for testing,which were 3 weeks old,5 weeks old and 7 weeks old,twelve in each group.The forepaw-reaching reflex test was used to detect whether the visual function of the mice was normal in each group.Immunohistochemical technique was used to detect the expression of IGF2 protein and its receptor in the lateral geniculate body of normal mice at week 3,5 and 7 postnatal,and to analyze the expression of the protein of IGF2 and its receptor in each part of the lateral geniculate body.Results The expression of IGF2 protein in the dorsal lateral geniculate nucleus decreased significantly at week 5 postnatal and increased significantly at week 7 postnatal,and increased gradually over time at week 5 and week 7 postnatal in the ventral geniculate nucleus.The expression of IGF2 receptor protein in the dorsal lateral geniculate nucleus and ventral nucleus increased significantly at week 5 postnatal,and at week 7 postnatal,the expression of IGF2 receptor decreased to week 3 level in lateral geniculate body of mice.Conclusion The expression of IGF2 and its receptor in lateral geniculate body of mice during critical period of visual development changed dynamically,and the expression patterns of IGF2 and its receptor in different parts of LGB were not completely consistent.The expression of IGF2 and its receptors may be related to the plasticity of visual development in mice.