Sharma Sumit, Ball Sherry L, Peachey Neal S
Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44106, USA.
Vis Neurosci. 2005 Sep-Oct;22(5):631-6. doi: 10.1017/S0952523805225129.
Electroretinography provides a useful noninvasive approach to evaluate cone pathway activity. Despite wide application of the cone ERG to characterize retinal function in transgenic mice and mouse models of human hereditary retinal disease, the cellular origins of the mouse cone ERG have not been well defined. Here, we address this issue using a pharmacological approach that has been previously applied to other species. Agents that block receptor activation at well-defined retinal loci were dissolved in saline and injected into the vitreous of anesthetized adult BALBc/By J mice; cone ERGs were recorded 1-2 h later. Analysis of the resulting waveforms indicated that the mouse cone ERG includes a cornea-negative component that is derived from the activity of cone photoreceptors and retinal glial (Müller) cells. Similar to other species, activity of cone depolarizing bipolar cells contributes a large amplitude cornea-positive potential to the mouse cone ERG. In contrast to primate but similar to rat, the mouse cone ERG includes only a small contribution from hyperpolarizing bipolar cell activity. The inner retina appears to contribute to both the a- and b-waves of the mouse cone ERG. These results provide a foundation for interpreting changes in the waveform of the mouse cone ERG that may be observed following genetic alteration or other experimental treatment.
视网膜电图提供了一种有用的非侵入性方法来评估视锥细胞通路的活性。尽管视锥细胞视网膜电图在转基因小鼠和人类遗传性视网膜疾病的小鼠模型中广泛应用于表征视网膜功能，但小鼠视锥细胞视网膜电图的细胞起源尚未得到很好的界定。在这里，我们使用一种先前已应用于其他物种的药理学方法来解决这个问题。将在明确的视网膜位点阻断受体激活的试剂溶解在盐水中，并注射到麻醉的成年BALBc/By J小鼠的玻璃体中；1-2小时后记录视锥细胞视网膜电图。对所得波形的分析表明，小鼠视锥细胞视网膜电图包括一个角膜负向成分，该成分源自视锥光感受器和视网膜神经胶质（穆勒）细胞的活性。与其他物种相似，视锥去极化双极细胞的活性对小鼠视锥细胞视网膜电图贡献了一个大振幅的角膜正向电位。与灵长类动物不同但与大鼠相似，小鼠视锥细胞视网膜电图仅包含来自超极化双极细胞活性的少量贡献。视网膜内层似乎对视锥细胞视网膜电图的a波和b波都有贡献。这些结果为解释在基因改变或其他实验处理后可能观察到的小鼠视锥细胞视网膜电图波形变化奠定了基础。
