正常大鼠发育过程中视网膜电图a波的特点

Characteristics of the electroretinography a-wave during development in normal rats

目的观察正常大鼠发育过程中暗适应视网膜电图（ERG）a波的变化特点。方法实验研究。采用RETI-scan系统，环形角膜电极和不锈钢针状电极，对8组不同日龄大鼠（21、25、32、35、37、46、60及90d）记录不同刺激光强度下（0．03、0．95、3和9．5cd·S·m^-2）的暗适应ERG。导出数据，先采用Matlab7．4对数据进行预处理，然后根据数学模型使用Excel提供的规划求解模型拟合a波并分析模型中的2个参数：饱和波幅（Rmp3）与敏感度（S）。结果不同刺激光强度下Rmp3的最小值均出现在25日龄大鼠，光强为0．03cd·S·m^-2时其最大值出现在60日龄大鼠，余则出现在46日龄大鼠。8组大鼠的S均与刺激光强度呈线性关系（S=ks·Ⅰ＋bs），除60日龄大鼠外，曲线的斜率ks基本保持不变，约为0．09，日龄主要影响常量bs。结论正常大鼠ERGa波的饱和波幅及敏感度均不同程度地受日龄的影响。

Objective To investigate the characteristics of the dark-adapted electroretinography （ERG） a-wave during development in normal rats. Methods In this experimental study, the dark-adapted ERG of eight groups of Rcs-rdy＋-p＋rats at different ages （21, 25, 32, 35, 37, 46, 60 and 90 d） were recorded by a series of flashes （0.03, 0.95, 3 and 9.5 cd·s·m^-2） using a RETI-sean system and gold-foil ring form corneal recording electrode and a stainless steel needle electrode custom made in the lab. Data were exported to the computer and processing by a Matlab 7.4 software, then were modeled with the solver model of Excel and two parameters of the a-wave were analyzed： the saturation a-wave amplitude （Rmp3） and sensitivity （S）. Results The minimum Rmp3 appeared at 25 days old group. When the intensity of light was 0.03 ed·s·m^-2, the maximum of Rmp3 appeared at 60 days old group, under other intensity of light, it appeared at 46 days old group. It showed that there was a linear relationship between the sensitivity of the 8 groups and intensity of the light （S=ks·Ⅰ＋bs）. Excluding the 60 days old group, the effects of age was mainly on the constant-bs but not the slope of the curve-ks, ks was equal to 0.09. Conclusion The Rmp3 and sensitivity of a-wave of the ERG can be affected by age with vary degrees.