Functional Circuitry of Long-Range Connections in the Retina

视网膜长距离连接的功能电路

• 批准号: 10189598
• 负责人: Jonathan B Demb
• 金额: $ 47.99万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10189598
• 关键词: Action Potentials; Alleles; Amacrine Cells; Anatomy; Area; Axon; Behavior; Brain; Cell physiology; Cells; Data; Dendrites; Development; Diabetic Retinopathy; Electron Microscopy; Electrophysiology (science); Enterobacteria phage P1 Cre recombinase; Excitatory Synapse; Exhibits; Eye diseases; FLP recombinase; Face; Family; Foundations; Genetic; Genetic Structures; Genetic Techniques; Glaucoma; Goals; Image; Individual; Interneurons; Label; Laboratories; Mediating; Methods; Microscopy; Modeling; Molecular; Morphology; Mus; Network-based; Neurons; Optics; Pathway interactions; Photoreceptors; Problem Solving; Process; Property; Prosthesis; Reporter; Resolution; Retina; Retinitis Pigmentosa; Role; Scanning; Shapes; Signal Transduction; Stimulus; Structure; Substance P Receptor; Synapses; Testing; Vision; Visual; base; cell type; experimental study; ganglion cell; genetic approach; insight; interdisciplinary approach; kappa opioid receptors; millimeter; neural circuit; neurochemistry; novel; operation; optogenetics; reconstruction; response; statistics; tool; transcription factor; visual processing

Our broad goal is to understand how neural circuits in the retina perform the visual computations that generate healthy vision. Our specific goal in this proposal is to reveal the role of wide-field amacrine cells (WACs) in retinal processing. WACs, a class of GABAergic interneuron, are the largest cells in the retina, and in the mouse they can span nearly half of the retinal area. A conventional model proposes that WACs encode contrast locally over their central dendrites and then spread inhibition globally by action potential (spike)- dependent signaling down millimeter-long axons. This global GABAergic inhibition would tune excitatory (bipolar cell → ganglion cell) retinal circuits and thereby shape ganglion cell responses to local features based on the global statistics of the visual scene. It has been difficult to evaluate WAC function systematically, however, because the field lacks tools for targeting specific WAC types for functional and structural studies. Here, we solve this problem by developing intersectional genetic strategies to label a diverse family of WACs that express the transcription factor Bhlhb5 in the mouse retina. Using a combination of Flp and Cre recombinase expression, in conjunction with dual-reporter alleles, we developed methods to identify Bhlhb5- expressing WAC (B5 WAC) subtypes, which together comprise ~20% of all amacrine cells. Our preliminary studies challenge the conventional model of WAC function. Specifically, we identified a subset of B5 WACs that are non-spiking cells. Ca2+ indicator imaging demonstrates that non-spiking B5 WACs exhibit localized changes in [Ca2+] in dendritic compartments that can be tuned to stimulus properties (e.g., orientation tuning), leading to the hypothesis that despite their large size, these cells are involved primarily in local processing of visual features at multiple points within their wide arbors. Proposed experiments will identify spiking and non-spiking B5 WAC types based on combined genetic, structural and functional criteria and reveal novel roles for these interneurons in retinal function. We will test specific hypotheses about B5 WAC synaptic organization using intersectional optogenetic experiments combined with high-resolution Scanning Block-face Electron Microscopy (SBEM) and STochastic Optical Reconstruction Microscopy (STORM). Our multidisciplinary approach, with unique contributions from four laboratories, will yield new insights into the circuit functions of the retina's largest neurons.

我们的广泛目标是了解视网膜中的神经电路如何执行产生的视觉计算 健康的视力。我们在此提案中的具体目标是揭示宽场无链氨酸细胞（WAC）在 视网膜处理。 WACS是一类GABA能中间神经元，是视网膜中最大的细胞，在 它们可以跨越视网膜区域的一半。 WACS编码的常规模型建议 在其中央树突上局部对比，然后通过动作电位（SPIKE）在全球范围内传播抑制作用 - 依赖性信号向下毫米长的轴突。这种全球GABA能抑制作用会调节兴奋性 （双极单元→神经节电池）视网膜电路，从而形成了神经节细胞对基于局部特征的响应 关于视觉场景的全球统计数据。很难系统地评估WAC功能， 但是，由于该领域缺少用于针对功能和结构研究的特定WAC类型的工具。 在这里，我们通过开发交叉遗传策略来解决这个问题 在小鼠视网膜中表达转录因子BHLHB5。结合FLP和CRE 重组酶的表达，与双重变形蛋白等位基因一起，我们开发了鉴定BHLHB5-的方法 表达WAC（B5 WAC）亚型，共同完成了所有无麦大型细胞的20％。 我们的初步研究挑战了WAC功能的常规模型。具体来说，我们确定了一个子集 非加速细胞的B5 WAC。 CA2+指示剂成像证明了非加速B5 WACS展示 在树突室中[Ca2+]的局部变化，可以调节以刺激特性（例如，方向 调整），导致假设渴望它们的大小，这些细胞主要涉及局部 在其宽阔的乔木中多个点处理视觉特征。建议的实验将确定 基于遗传，结构和功能标准的峰值和非加速B5 WAC类型以及 揭示这些中间神经元在残留功能中的新作用。我们将测试有关B5 WAC的特定假设 突触组织使用相互遗传实验与高分辨率扫描结合 块面电子显微镜（SBEM）和随机光学重建显微镜（Storm）。我们的 具有四个实验室的独特贡献的多学科方法将为您提供新的见解 视网膜最大的神经元的电路功能。