近视大鼠模型的初级视皮层功能可塑性观察

Observation on the plasticity of primary visual cortex function in a rat model of myopia

目的:建立近视大鼠模型,初步探讨近视的中枢神经机制是否与初级视皮层(Vl)有关。方法:20只SD乳大鼠随机分成对照组和近视模型组,每组10只。通过测量两组大鼠眼轴长度鉴定近视大鼠模型;通过在体细胞外记录技术和酶联免疫吸附实验(ELISA)分析近视的初级视皮层机制。结果:造模9周后,与对照组(6.08±0.07)mm相比,近视模型组大鼠眼轴增长至(6.27±0.13)mm(P<0.01);与对照组(18.67±8.25)Hz相比,近视模型组大鼠视皮层V1区神经元放电频率降低至(9.82±4.72)Hz(P<0.05);电刺激正常大鼠V1区,ELISA结果显示,与对照组(762.28±29.77)pg/mL相比,近视模型组V1区谷氨酸(Glu)表达增加至(818.81±33.50)pg/mL(P<0.01)。结论:低频闪烁红光成功诱导大鼠近视形成,这种近视形成可能与初级视皮层神经元活动有关。

Objective:To preliminarily investigate whether the central nervous mechanism of myopia is related to the primary visual cortex(V1)based on rat model of myopia.Methods:Twenty neonatal SD rats were randomly divided into control group and myopia group(n=10 in each group).The myopia rat model was identified by measuring the axial length of two groups of rats.The mechanism of primary visual cortex underlying the myopia was analyzed by using an in vivo extracellular recording technique and enzyme-linked immunosorbent assay(ELISA).Results:Nine weeks after modeling,the axial length(AL)in the myopia group increased significantly to(6.27±0.13)mm,compared to that of control group[(6.08±0.07)mm,(P<0.01)],yet the discharge frequency of neurons in the V1 region of the myopia group decreased significantly as compared with control group[(9.82±4.72)Hz vs.(18.67±8.25)Hz,(P<0.05)].When the V1 area of normal rats was electrically stimulated,the ELISA results showed that the expression of glutamate(Glu)in myopia group was increased compared to control group[(818.81±33.50)pg/mL vs.(762.28±29.77)pg/mL,(P<0.01)].Conclusion:Low-frequency flickering red light successfully induced myopia in rats,which may be related to neuronal activity in V1 area.