Porciatti Vittorio, Chou Tsung-Han, Feuer William J
Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Mol Vis. 2010 Dec 31;16:2939-47.
To characterize differences in retinal ganglion cell (RGC) function in mouse strains relevant to disease models. C57BL/6J (B6) and DBA/2J (D2) are the two most common mouse strains; D2 has two mutated genes, tyrosinase-related protein 1 (Tyrp1) and glycoprotein non-metastatic melanoma protein B (Gpnmb), causing iris disease and intraocular pressure (IOP) elevation after 6 months of age that results in RGC degeneration, and is the most widely used model of glaucoma. DBA/2J.Gpnmb(+) (D2.Gpnmb(+)) is the wild type for the Gpnmb mutation and does not develop IOP elevation and glaucoma.
Young (2-4 months of age) B6, D2, and D2.Gpnmb(+) mice (n=6 for each group) were tested with pattern electroretinogram (PERG) in response to different contrasts and spatial frequencies. PERG amplitude and latency dependencies on stimulus parameters (transfer functions) were established for each mouse strain, together with corresponding thresholds for contrast and spatial resolution.
PERG analysis showed that B6, D2, and D2.Gpnmb(+) mice had comparable contrast threshold and spatial resolution. Suprathreshold spatial contrast processing, however, had different characteristics in the three strains. PERG amplitude and latency changes with increasing contrast were different between B6 and D2 as well as between D2 and D2.Gpnmb(+).
B6, D2, and D2.Gpnmb(+) mice have different characteristics of PERG spatial contrast processing consistent with different mechanisms of contrast gain control. This may imply differences in the activity of underlying PERG generators and synaptic circuitry in the inner retina.
表征与疾病模型相关的小鼠品系中视网膜神经节细胞（RGC）功能的差异。C57BL/6J（B6）和DBA/2J（D2）是两种最常见的小鼠品系；D2有两个突变基因，即酪氨酸酶相关蛋白1（Tyrp1）和糖蛋白非转移性黑色素瘤蛋白B（Gpnmb），导致6月龄后出现虹膜疾病和眼压（IOP）升高，进而导致RGC退化，是使用最广泛的青光眼模型。DBA/2J.Gpnmb(+)（D2.Gpnmb(+)）是Gpnmb突变的野生型，不会出现IOP升高和青光眼。
对年轻（2 - 4月龄）的B6、D2和D2.Gpnmb(+)小鼠（每组n = 6）进行图形视网膜电图（PERG）测试，以响应不同的对比度和空间频率。为每个小鼠品系建立了PERG振幅和潜伏期对刺激参数的依赖性（传递函数），以及相应的对比度和空间分辨率阈值。
PERG分析表明，B6、D2和D2.Gpnmb(+)小鼠具有相当的对比度阈值和空间分辨率。然而，超阈值空间对比度处理在这三个品系中具有不同的特征。B6和D2之间以及D2和D2.Gpnmb(+)之间，PERG振幅和潜伏期随对比度增加的变化是不同的。
B6、D2和D2.Gpnmb(+)小鼠在PERG空间对比度处理方面具有不同的特征，这与对比度增益控制的不同机制一致。这可能意味着视网膜内层潜在的PERG发生器和突触回路的活动存在差异。
