似昼夜节律对正常SD大鼠视觉电生理的影响

Effects of circadian rhythm on the visual electrophysiology of the rats

目的研究一天中不同时间段记录的正常SD大鼠视觉电生理结果间的区别，以揭示似昼夜节律对视网膜功能的影响。方法实验研究。24只SD大鼠随机分为4组，每组6只（6眼）。对各组分别于8：00～12：00（上午）、14：00～18：00（下午）、20：00～24：00（午夜）、2：00—6：00（凌晨）4个时间段记录不同刺激参数的视觉电生理。各组间差异采用单因素方差分析，两两间差异采用posthoc检验分析。结果下午及午夜的暗适应视网膜电图a波和b波的幅值要高于上午（P〈0．05），振荡电位O2波幅值在午夜最高（P〈0．05），20 Hz闪烁视网膜电图反应P1波和视觉诱发电位N1波的潜伏期凌晨明显较上午短（P〈0．05）。结论SD大鼠的视锥和视杆功能变化与似昼夜节律有关，其在夜间要较白天活跃，视觉电生理记录最好固定在每天的同一时间段进行。

Objective To investigate the effect of circadian rhythm on the visual electrophysiology of the SD rat. Methods In this experimental study, 24 SD rats were divided into 4 groups randomly, 6 rats （6 eyes） in each group. Visual electrophysiology of the 4 groups was recorded at different time periods respetively with different stimulation parameters ： 8 ： 00-12 ： 00 （morning）, 14 ： 00-18 ： 00 （afternoon）, 20：00-24：00 （midnight）, and 2：00-6：00 （before dawn）. ANOVA was used to analyze the differences among the groups and post hoc analysis was used to compare the difference between any two groups. Results The a-wave and b-wave amplitudes of dark-adapted electroretinogram （ERG） was higher in the afternoon and midnight than in the morning. The O2 amplitude of the oscillatory potentials was highest at midnight. The latency of the PI wave of the 20 Hz flicker ERG reaction and the N1 wave of the visual evoked potential during the before draw was significantly shorter than that in the morning. Conclusion The cone and rod functions in SD rats are related to circadian rhythm, and it is more active at night than during the day. It is better to schedule visual electrophysiological recordings in SD rats during the same period of the day.