小鼠瞳孔直径变化分析系统在C57BL/6小鼠瞳孔对光反射功能评价中的作用

摘要

背景 瞳孔对光反射检查在诊断和评价视觉系统及神经系统疾病中有重要价值.小鼠动物模型的视觉系统评价技术复杂,其神经系统的评价过程受多种因素的影响,准确测量瞳孔对光反射对于快速评价动物模型的视网膜功能及诊断神经系统病变有重要意义. 目的 探讨瞳孔直径变化分析系统在小鼠瞳孔对光反射测量中的应用价值及不同的刺激光亮度对相关参数的影响. 方法 纳入10只SPF级雄性C57BL/6小鼠,受检前进行2h暗适应,然后采用瞳孔直径变化分析装置对每只小鼠均依次给予2、8、32、128、256 cd/m2 5个光亮度的白色光刺激,每次刺激与上次刺激之间至少间隔60 s,每次持续时间为100 ms,同时在暗环境中采用红外线摄像头及视频捕捉卡获取小鼠瞳孔对光反射过程的数字图像,摄取速度为60帧/s,以*.AVI格式保存文件.运用自行开发的软件系统确定瞳孔直径并输出瞳孔对光反射动态变化曲线图,获取瞳孔直径初始值(R1)、收缩幅度(CA)、收缩速度(CV)、光刺激开始时到瞳孔开始收缩时之间的潜伏期(T1)、开始收缩时至最大收缩速度时的时间(T2)、开始收缩时到收缩最大程度时的时间(T3)、收缩最大程度时到瞳孔复张10.1％ R1时的时间(RT)及快速复张速度(RV)等参数,用Searman秩相关法分析刺激光亮度与各参数间的相关性. 结果 5个刺激光亮度组小鼠的R1值变化总体比较差异无统计学意义(F=1.117,P=0.361).刺激光亮度等级与CA变化值间呈线性正相关(r=0.508,P＜0.01),与CV及RV均呈线性负相关(r =-0.625、-0.609,P＜0.01).不同刺激光亮度组间T1值、T2值的总体比较差异均无统计学意义(F=0.202,P=0.936;F=1.584,P=0.195),刺激光亮度等级与T3值变化及RT值均呈线性正相关(r=0.791、0.609,P＜0.01).结论 瞳孔直径变化分析系统可以反映C57B L/6小鼠的瞳孔对光反射功能变化.小鼠瞳孔对光反射动态曲线分析参数受刺激光亮度的影响.瞳孔直径变化分析系统可作为视觉系统及神经系统功能评价小鼠模型的检测工具.%Background Pupillary light reflex has been widely used in the diagnosis and evaluation of visual system and nervous system diseases.However,in animal experiments,functional evaluation of the visual system and nervous system needs more advanced technology and are affected by many factors.Objective This study was to explore the use of the dynamic pupillometer in evaluating pupillary light reflex and to discuss the influence of brightness of stimulate on relevant curve parameters in C57BL/6 mouse.Methods Ten healthy SPF male C57BL/6 mice were collected in this experiment.White light of five luminance levels (2,8,32,128,256 cd/m2) was used to stimulate the mice following a 2-hour dark adaptation.The stimulation was given at the 60-second intervals,for a duration of 100 ms at every stimulation.An infrared camera and video capture card were used to capture digital images during the measuring process in a scotopic environment,at a speed of 60 frames per second.Measuring outcome was saved in the " *.AVI" format.A software that was developed by our group was used to determine pupil diameter and output pupillary light reflex curve offline.Pupil initial diameter (R1),constriction amplitude (CA),constriction velocity (CV),latency (T1),time for maximum velocity (T2),time for maximum constriction (T3),time for maximun con-striction to 10.1％ R1 re-dilation (RT)and re-dilation velocity (RV)were assessed,and the correlations between luminosity and measuring parameters were analyzed using the Spearman rank correlation.The use of animals followed the Regulations for thd Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results R1 values showed no statistically significant difference among the 5 different luminosity groups(F=1.117,P=0.361).A positive linear correlation was found between stimulating luminosity and CA(r=0.508,P＜ 0.01),but negative correlations were seen between stimulating luminosity and CV or RV (r=-0.625,-0.609,P＜0.01).T1 and T2 values in the 5 different luminosity groups were not statistically significant (F =0.202,P =0.936 ; F =1.584,P =0.195).The different levels of stimulating luminosity showed positive linear correlations with T3 and RT values (r =0.791,0.609,P＜ 0.01).Conclusions The dynamic pupillometer can quantitatively measure the pupillary light reflex of C57BL/6 mice.The pupillary light reflex dynamic curve parameters of mouse were affected by stimulus luminosity levels.These outcomes offer a basis for the application of the dynamic pupillometer system for measuring pupillary light reflex in animal models.