The electroretinogram (ERG) has been employed for years to collect information about retinal function and pathology. The usefulness of this noninvasive test depends on our understanding of the cell sources that generate the ERG. Important contributors to the ERG are glial Müller cells (MCs), which are capable of generating substantial transretinal potentials in response to light-induced changes in extracellular K+ concentration ([K+]o). For instance, the MCs generate the slow PIII (sPIII) component of the ERG as a reaction to a photoreceptor-induced [K+]o decrease in the subretinal space. Similarly, an increase of [K+]o related to activity of postreceptor retinal neurons also produces transretinal glial currents, which can potentially influence the amplitude and shape of the b-wave, one of the most frequently analyzed ERG components. Although it is well documented that the majority of the b-wave originates from On-bipolar cells, some contribution from MCs was suggested many years ago and has never been experimentally rejected. In this work, detailed information about light-evoked [K+]o changes in the isolated mouse retina was collected and then analyzed with a relatively simple linear electrical model of MCs. The results demonstrate that the cornea-positive potential generated by MCs is too small to contribute noticeably to the b-wave. The analysis also explains why MCs produce the large cornea-negative sPIII subcomponent of the ERG, but no substantial cornea-positive potential.

中文翻译：

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K+ 依赖性穆勒细胞生成的视网膜电图成分

视网膜电图（ERG）多年来一直用于收集有关视网膜功能和病理学的信息。这种非侵入性测试的有用性取决于我们对产生 ERG 的细胞来源的理解。ERG 的重要贡献者是胶质 Müller 细胞 (MC)，它们能够响应光诱导的细胞外 K 变化而产生大量的跨视网膜电位+浓度（[K+]哦）。例如，MCs 产生 ERG 的慢速 PIII (sPIII) 成分，作为对光感受器诱导的 [K+]哦视网膜下间隙减少。同样，[K+]哦与感受器后视网膜神经元活动相关的神经元也会产生跨视网膜神经胶质电流，这可能会影响 b 波的幅度和形状，b 波是最常分析的 ERG 成分之一。尽管有充分证据表明大多数 b 波源自双极细胞，但多年前就提出了 MC 的一些贡献，并且从未在实验上被拒绝。在这项工作中，有关光诱发的详细信息[K+]哦收集离体小鼠视网膜的变化，然后使用相对简单的 MC 线性电模型进行分析。结果表明，MC 产生的角膜正电势太小，无法对 b 波产生明显贡献。该分析还解释了为什么 MC 产生 ERG 的大角膜阴性 sPIII 子成分，但没有大量角膜阳性潜力。