Extracellular K+ activity changes related to electroretinogram components. II. Rabbit (E-type) retinas.
Extracellular K+ activity changes related to electroretinogram components. II. Rabbit (E-type) retinas.
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DOI：
10.1085/jgp.85.6.911
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发表时间：
1985-06
期刊：
影响因子：
--
通讯作者：
Bloomfield S
中科院分区：
文献类型：
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作者：
Dick E;Miller RF;Bloomfield S
视网膜电图（ERG）和细胞外钾活性（K+O）的测量进行了分离的灌流兔眼杯制剂在控制条件下，并在应用的药物，选择性地修改光响应视网膜网络。光诱发的K+o的变化，在兔（E型）视网膜类似于先前描述的两栖动物（I型）视网膜。光诱发的K+o变化的不同成分可以根据视网膜深度、V与log I特性及其对药理学试剂的反应来区分。我们发现两个可分离的来源光诱发的细胞外K+的增加：近端源和远端源。远端光诱发的K+O增加的性质与其启动通过Muller细胞的K+介导的电流的假设一致，该电流被检测为视网膜电图b波的初级电压。这些实验也支持以前的研究表明，角膜阳性成分的c波和角膜阴性慢PIII电位的结果从K+介导的影响，分别对视网膜色素上皮细胞和穆勒细胞。
Electroretinogram (ERG) and extracellular potassium activity (K+o) measurements were carried out in isolated superfused rabbit eyecup preparations under control conditions and during the application of pharmacological agents that selectively modify the light-responsive retinal network. Light-evoked K+o changes in the rabbit (E-type) retina resemble those previously described in amphibian (I-type) retinas. Different components of the light-evoked K+o changes can be distinguished on the bases of retinal depth, V vs. log I properties, and their responses to pharmacological agents. We find two separable sources of light-evoked increases in extracellular K+: a proximal source and a distal source. The properties of the distal light-evoked K+o increase are consistent with the hypothesis that it initiates a K+- mediated current through Muller cells that is detected as the primary voltage of the electroretinographic b-wave. These experiments also support previous studies indicating that both the corneal-positive component of c-wave and the corneal-negative slow PIII potential result from K+-mediated influences on, respectively, the retinal pigment epithelium and Muller cells.