Supernormal ERG oscillatory potentials in transgenic rabbit with rhodopsin P347L mutation and retinal degeneration.
Supernormal ERG oscillatory potentials in transgenic rabbit with rhodopsin P347L mutation and retinal degeneration.
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DOI：
10.1167/iovs.09-3458
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发表时间：
2009-09
影响因子：
4.4
通讯作者：
T. Sakai;M. Kondo;S. Ueno;Toshiyuki Koyasu;K. Komeima;H. Terasaki
中科院分区：
文献类型：
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作者：
T. Sakai;M. Kondo;S. Ueno;Toshiyuki Koyasu;K. Komeima;H. Terasaki
目的用视网膜电流图(ERG)检测视紫红质P347L转基因(TG)兔视网膜变性模型的视网膜特性。方法记录12~48周龄野生型(WT)兔和TG兔的全场ERG。用Hood和Birch的a波拟合模型对a波进行了分析。用Michaelis-Menten方程分析b波的刺激-反应函数。减去a波后用数字滤波提取振荡电位(OPs)。玻璃体腔注射L-2氨基-4-膦酸丁酸、顺式-2，3-哌啶二酸、γ-氨基丁酸或柠檬酸河豚毒素前后记录OPs。结果TG兔ERG各成分均随年龄增长而递减，a波较b波受影响更大，OPs保存最好。值得注意的是，12周龄时，TG兔的OP波幅总和显著大于WT兔。玻璃体内注射APB、PDA或GABA后，TG兔OPs波幅的变化与WT兔无明显差异。但注射TTX后，TG兔OPs波幅下降幅度(65.3%)明显大于WT兔(28.6%)。结论TG兔视网膜内神经元的改变导致了较大的OPS。TTX对TG兔OP波幅的影响较大，提示TG兔OP异常可能与感光细胞变性后视网膜内侧棘波神经元的继发性改变有关。
PURPOSE To determine the properties of the retina of a rhodopsin P347L transgenic (Tg) rabbit model of retinal degeneration by electroretinography (ERG). METHODS Full-field ERGs were recorded in 12- to 48-week-old wild-type (WT) and Tg rabbits. The a-wave was analyzed by the a-wave fitting model of Hood and Birch. The stimulus-response function of the b-wave was analyzed by the Michaelis-Menten equation. Oscillatory potentials (OPs) were extracted by digital filtering after subtracting the a-wave. OPs were also recorded before and after an intravitreal injection of l-2 amino-4-phosphonobutyric acid (APB), cis-2,3 piperidine dicarboxylic acid (PDA), gamma-amino butyric acid (GABA), or tetrodotoxin citrate (TTX). RESULTS All the ERG components of Tg rabbits decreased progressively with age with the a-wave more affected than the b-wave, and the OPs were most preserved. Of interest, the summed OP amplitudes of the Tg rabbits were significantly larger than those of WT rabbits when they were 12 weeks of age. The changes in the amplitudes of the OPs after intravitreal injections of APB, PDA, or GABA in Tg rabbits did not differ significantly from those of WT rabbits. However, injection of TTX resulted in a significantly larger amplitude reduction of the OPs in Tg (65.3%) than in WT (28.6%) rabbits. CONCLUSIONS The significantly larger OPs in Tg rabbits resulted from alterations in the inner retinal neurons. The greater effect of TTX on the OP amplitudes in Tg rabbits suggests that the supernormal OPs in Tg rabbits may be related to secondary changes in the spiking neurons of the inner retina after photoreceptor degeneration.