Ball S L, Petry H M
Department of Ophthalmology and Visual Sciences, University of Louisville, Kentucky 40292, USA.
Invest Ophthalmol Vis Sci. 2000 Feb;41(2):610-7.
To assess the applicability of multifocal electroretinograms (mfERGs) for evaluation of function in this small-eyed animal with a rod-dominant retina that is often used to model retinal diseases.
Noninvasive monocular mfERGs were recorded in anesthetized albino (Sprague-Dawley) and pigmented (Long Evans) rats. Achromatic stimuli subtending a 49 degrees by 53 degrees field consisted of 61 hexagons that were generated and presented (at varying rates and luminances) using a Visual Evoked Response Imaging System (VERIS; EDI, San Mateo, CA). The VERIS also was used to calculate individual responses and for analysis.
mfERGs were recorded from pigmented and albino rats by slowing the rate of stimulus presentation to allow for the slow recovery time of the rod system. In each rat strain, responses varied systematically with changes in stimulus parameters. Peak response amplitude increased as the rate of stimulation was slowed and as stimulus luminance was increased. Response latency decreased as stimulus intensity was increased. The local nature of the response was assessed by several independent measures.
The present work demonstrated the feasibility and limitations of using mfERG to assess topographical changes in the rat retina. It showed that despite the problems of the unavoidable self-adapting nature of the stimulus, the small eye of the animal, and the high potential for light scatter within the retina, multifocal responses with a good signal-to-noise ratio can be obtained from the rat.
评估多焦视网膜电图（mfERGs）在这种常被用于模拟视网膜疾病的具有以视杆细胞为主的视网膜的小眼动物中评估功能的适用性。
在麻醉的白化病（斯普拉格 - 道利）大鼠和有色（长 Evans）大鼠中记录无创单眼mfERGs。由61个六边形组成的、对49度×53度视野张角的消色差刺激，使用视觉诱发电位成像系统（VERIS；EDI，加利福尼亚州圣马特奥）生成并呈现（以不同速率和亮度）。VERIS还用于计算个体反应并进行分析。
通过减慢刺激呈现速率以适应视杆系统的缓慢恢复时间，在有色和白化病大鼠中记录到了mfERGs。在每个大鼠品系中，反应随刺激参数的变化而系统地变化。随着刺激速率减慢和刺激亮度增加，峰值反应幅度增加。随着刺激强度增加，反应潜伏期缩短。通过几种独立的测量方法评估了反应的局部性质。
目前的工作证明了使用mfERG评估大鼠视网膜地形图变化的可行性和局限性。研究表明，尽管存在刺激不可避免的自适应性质、动物的小眼以及视网膜内光散射可能性高这些问题，但仍可从大鼠获得具有良好信噪比的多焦点反应。
