The Mouse dc-Electroretinogram

描述（由申请人提供）：视网膜色素上皮（RPE）与正常视网膜功能所需的许多功能密切相关，包括光感受器和脉络膜循环之间的营养物和废物流动、视觉周期以及脱落外节盘的吞噬作用。此外，RPE特异性基因的突变与广泛的遗传性视网膜疾病有关，这些信息正在用于开发相应的小鼠模型。在本项目中，重点是由RPE响应于神经视网膜的活动而产生的电响应。虽然RPE功能的特定方面可以使用使用视网膜电图（ERG）来研究，该视网膜电图（ERG）使用直流耦合放大来记录，但这尚未应用于小鼠。此外，关于dc-ERG的不同组成部分的起源仍然存在根本问题。在目标1中，我们将研究正常野生型小鼠，以确定小鼠dc-ERG的刺激反应特征，以及这些发展的时间过程。在目标2中，我们将使用转导素和视紫红质的KO系以及其中视锥细胞群增加（rd 7）或减少（comas转基因）的突变体来检验小鼠dc-ERG主要由视杆光感受器活性启动的假设。在目标3中，我们将使用Kir4.1 KO小鼠来检验该通道参与c波生成的假设。在目的4中，我们将使用cftr KO小鼠和CFTR构建体的腺病毒递送来测试快速振荡由CFTR活性产生的假设。在目的5中，我们将使用dc-ERG记录来研究感光细胞变性与RPE功能变化之间的关系。首先，我们将研究A2 E在abcr突变小鼠中的积累如何改变RPE功能。接下来，我们将使用三种感光细胞退化率相似的小鼠来检验功能性RPE异常发生在早期阶段的假设。在两种情况下，主要缺陷存在于光感受器（rds/+和Bouse转基因小鼠）。在vitilligo小鼠中，RPE缺陷诱导了类似的感光细胞变性率。在这个项目完成后，我们希望已经确定了一个最佳的手段，用于记录小鼠dc-ERG在体内，有一个彻底的了解的过程，基础上的dc-ERG的不同组成部分，以及更完整的了解这些组件是如何受到影响的外部视网膜疾病。

DESCRIPTION (provided by applicant): The retinal pigment epithelium (RPE) is critically involved in many functions required for normal retinal function including the flow of nutrients and waste products between the photoreceptors and the choroidal circulation, the visual cycle, and the phagocytosis of shed outer segment disks. In addition, mutations in RPE-specific genes have been implicated in a wide range of hereditary retinal disease, and this information is being used to develop corresponding mouse models. In the present project, the focus is on the electrical responses generated by the RPE in response to activity of the neural retina. While specific aspects of RPE function may be studied using the electroretinogram (ERG) recorded using dc-coupled amplification, this has not been applied to the mouse. Moreover, fundamental questions remain regarding the origin of the different components of the dc-ERG. In Aim 1, we will study normal wild-type mice, to define the stimulus-response characteristics of the mouse dc-ERG, and the time course over which these develop. In Aim 2, we will test the hypothesis that the mouse dc-ERG is initiated primarily by rod photoreceptor activity, using KO lines for transducin and rhodopsin, and mutants in which the cone population is increased (rd7) or decreased (comas transgenic). In Aim 3, we will use Kir4.1 KO mice to test the hypothesis that this channel is involved in c-wave generation. In Aim 4, we will use cftr KO mice and adenoviral delivery of CFTR constructs to test the hypothesis that the fast oscillation is generated by CFTR activity. In Aim 5, we will use dc-ERG recordings to study the relationship between photoreceptor degeneration and changes in RPE function. First, we will examine how A2E accumulation in abcr-mutant mice alters RPE function. Next, we will test the hypothesis that functional RPE abnormalities occur at early stages using three lines of mice with similar rates of photoreceptor degeneration. In two, the primary defect resides in the photoreceptors (rds/+ and Bouse transgenic mice). In vitilligo mice, a similar rate of photoreceptor degeneration is induced by defect in the RPE. At the completion of this project, we expect to have defined an optimal means for recording the mouse dc-ERG in vivo, to have a thorough understanding of the processes that underlie the different components of the dc-ERG, and a more complete understanding of how these components are affected by disorders of the outer retina.