NEUROCHEMICAL PATHWAYS IN THE INNER RETINA

视网膜内层的神经化学通路

• 批准号: 6605711
• 负责人: NICHOLAS C. BRECHA
• 金额: $ 39万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-07-06 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6605711
• 关键词: G protein; Urodela; amacrine cells; electrophysiology; fluorimetry; genetically modified animals; immunocytochemistry; in situ hybridization; laboratory mouse; laboratory rabbit; laboratory rat; neural information processing; neurochemistry; neuropeptide receptor; neurotransmitter transport; nucleic acid probes; polymerase chain reaction; receptor expression; retina; retinal bipolar neuron; rod cell; somatostatin; visual fields; visual photoreceptor

DESCRIPTION (Adapted from the applicant's abstract): The overall goal of this program is to better understand visual image processing in the mammalian inner retina by defining and characterizing its transmitter systems, cell morphology and circuitry. The focus of these studies is on somatostatin (SRIF), a potent inhibitory transmitter localized to wide-field amacrine cells and its five G protein-coupled receptors, SSTR1-5. The proposed studies are focused on determining the presence of the SSTRs, their cellular expression patterns and relationship to SRIF-containing amacrine cell processes to address the hypothesis that SRIF has a paracrine mode of action and a modulatory influence at both the cellular and circuitry levels by acting at distinct SSTRs expressed by multiple cell populations. Investigations will also study the inhibitory actions of SRIF on intracellular Ca2+ levels in acutely isolated rodent rod bipolar cells and salamander photoreceptors, which strongly express SSTR2, to better define the modulatory action of SRIF at the cellular level. Specific aim 1 will determine and characterize SSTR1-SSTR5 mRNA tissue and cellular distribution using RT-PCR, RNA blot hybridization and in situ hybridization immunohistochemistry using the rodent retina. Specific aim 2 will investigate the sites of action of SRIF by defining the expression of SSTR1-SSTR5 and their relationship to SRIF fibers using immunohistochemistry in the rodent and rabbit retina. Specific aim 3 will investigate the inhibitory action of SRIF at the cellular level using acutely isolated rodent rod bipolar cells and salamander photoreceptors with fluorometric Ca2+ imaging techniques. Studies will characterize SRIF inhibition of a K+ stimulated intracellular Ca2+ increase in these cells, and SRIF's modulation of the Go/Gi G proteins that have been implicated in the cellular action of this peptide. Finally, studies will evaluate SRIF action utilizing SRRF-1 and SRRF-2 receptor agonists. These studies will use rod bipolar cells from normal and Go- or Gi-deficient mice with a gene disruption of the alpha-o, alpha-i1, alpha-i2 or alpha-i3 subunits, and from SSTR-2-deficient mice with a gene disruption of SSTR-2. Experiments will utilize sequence-specific RNA probes, antibodies, SRIF-1 and -2 receptor agonists, and a highly specific SSTR2 antagonist to accomplish the experimental objectives of this application. Proposed studies will provide new information about the role of peptides in the modulation of retinal cells and circuitry in the inner retina, thus providing the basis for a better understanding of visual image processing in the retina. These objectives are consistent with the health-related goals of the National Eye Institute to develop more effective treatments and ultimately to prevent retinal diseases.

描述（根据申请人的摘要改编）： 程序是更好地了解哺乳动物内部的视觉图像处理 视网膜通过定义和表征其发射器系统，细胞形态 和电路。这些研究的重点是生长抑素（SRIF），这是一种有效的 抑制性发射器局部位于广场无大细胞及其五g 蛋白质偶联受体，SSTR1-5。拟议的研究集中于 确定SSTR的存在，其细胞表达模式和 与含SRIF的含SRIF的无长际分酒细胞过程的关系以解决 假设SRIF具有旁分泌的作用方式和调节作用 通过在表达的不同SSTR上作用在细胞和电路水平上 由多个细胞群体。调查还将研究抑制 SRIF对急性分离啮齿动物杆的细胞内Ca2+水平的作用 强烈表达SSTR2的双极细胞和Salamander光感受器 更好地定义了SRIF在细胞水平上的调节作用。 特定的目标1将确定并表征Sstr1-Str5 mRNA组织和 使用RT-PCR，RNA印迹杂交和原位的细胞分布 使用啮齿动物视网膜杂交免疫组织化学。具体目标2将 通过定义的表达来研究SRIF的作用部位 SSTR1-STR5及其与SRIF纤维的关系，使用免疫组织化学 啮齿动物和兔子视网膜。特定目标3将调查抑制作用 SRIF使用急性分离的啮齿动物双极性在细胞水平上的作用 具有荧光CA2+成像技术的细胞和sal鼠光感受器。 研究将表征SRIF抑制K+刺激的细胞内CA2+ 增加这些细胞，以及SRIF对GO/GI G蛋白的调节 已经与该肽的细胞作用有关。最后，研究 将利用SRRF-1和SRRF-2受体激动剂评估SRIF动作。这些 研究将使用正常和GO或GI缺陷小鼠的杆双极细胞 与α-O，alpha-i1，alpha-i2或alpha-i3亚基的基因破坏有关 以及SSTR-2缺陷小鼠的基因破坏SSTR-2。实验 将利用序列特异性RNA探针，抗体，SRIF-1和-2受体 激动剂和高度特异的SSTR2拮抗剂来完成实验 此应用程序的目标。拟议的研究将提供新的信息 关于肽在视网膜细胞和电路调节中的作用 内部视网膜，从而为更好地理解视觉提供了基础 视网膜中的图像处理。这些目标与 国家眼科研究所与健康相关的目标，以发展更有效 治疗并最终预防视网膜疾病。