Ueno Shinji, Koyasu Toshiyuki, Kominami Taro, Sakai Takao, Kondo Mineo, Yasuda Shunsuke, Terasaki Hiroko
Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Vision Res. 2013 Oct 18;91:118-23. doi: 10.1016/j.visres.2013.08.006. Epub 2013 Aug 21.
A rhodopsin P347L transgenic (Tg) rabbit, a model of retinitis pigmentosa, has been generated in our laboratory. The purpose of this study was to determine the properties of focal areas of the retina in this rabbit model during the course of retinal degeneration. To accomplish this, we recorded focal ERGs from wild-type (WT) and Tg rabbits at ages 3, 6, and 12 months. A 15° stimulus spot was used to elicit the focal ERGs from the center of the visual streak and from four surrounding areas. We found that the amplitudes of the focal cone ERG b-waves and oscillatory potentials (OPs) of the Tg rabbits in the five areas decreased progressively with increasing age and became almost non-recordable at 12 months. There were no significant regional differences in the b-waves of Tg rabbits recorded from the 5 areas. The amplitudes of the OPs were better preserved than the b-waves and the OPs/b-wave ratio was higher than that in WT rabbits at every recording area. The summed OPs amplitudes, which most likely originate from the amacrine and/or ganglion cells, recorded from the area superior to the optic disc was significantly larger than that from other areas at 3- and 6-months-old. This indicated that the inner retinal neurons were not altered equally after photoreceptor degeneration in this rabbit model.
我们实验室培育出了一种视紫红质P347L转基因（Tg）兔，它是视网膜色素变性的模型。本研究的目的是确定在视网膜变性过程中该兔模型视网膜局部区域的特性。为实现这一目的，我们在3、6和12月龄时记录了野生型（WT）和Tg兔的局部视网膜电图（ERG）。使用一个15°的刺激光斑从视锥中央和四个周围区域引出局部ERG。我们发现，Tg兔这五个区域的局部视锥ERG b波和振荡电位（OP）的振幅随年龄增长逐渐降低，在12月龄时几乎无法记录。从Tg兔这5个区域记录的b波没有显著的区域差异。在每个记录区域，OP的振幅比b波保存得更好，且OP/b波比值高于WT兔。从视盘上方区域记录的总和OP振幅，很可能起源于无长突细胞和/或神经节细胞，在3月龄和6月龄时显著大于其他区域。这表明在该兔模型中，光感受器变性后视网膜内层神经元的变化并不相同。
