Parallel pathways in visual cortex: functional connectivity of output pathways fr

项目总结 了解大脑皮层神经回路的组织原理对于理解它们的 计算功能。这一原理为致力于生成的“连接学”的新领域提供了信息 不同比例的大脑或其子部分的接线图。 在灵长类动物的视觉皮质中，V1和V2区将它们从视网膜接收的信息分发给几乎所有的 更高的区域，将这些信息分类成用于空间和物体视觉的背侧和腹侧处理流， 分别进行了分析。这个应用程序的目标是揭示解剖和功能连接的规则 对于V1和V2输出通路，为了了解这些区域如何精炼和重组视网膜 信号进入视觉处理流，以及这些通路如何有助于创建复杂的接受器 较高区域神经元的场(RF)特性。从V1到V2的平行路径投影到DISTINCT 细胞色素氧化酶条纹(粗、细、淡)。在前一次赠款期间，我们发现了4个 V1和V2之间的分离通路。我们还发现了V1的专门功能组织 与粗纹和淡纹有关的通路可能是V2RF对倾斜和弯曲反应的基础 等高线。这项建议建立在这些发现的基础上。目标1的目标是了解单个V1细胞是如何 通过确定单个V1输出细胞的轴突和树突布局，有助于生成V2 RF V1和V2方向贴图。我们将在介镜上提供第一个全面的解剖学描述 投射到特定V2条纹的V1细胞的规模，包括V1内和V2内轴突分支 确定了V1和V2中的细胞类型及其功能组织。此信息将提供 深入了解前馈机制与V2内机制在V2 RFs生成中的作用，以及 V1内电路和V1到V2电路对轮廓处理的贡献。然后我们将调查是否 这4条通路的解剖和功能分离在V2下游维持或消失。的目标是 AIM2是为了确定我们最近得到的两种V2苍白条纹类型的面积投影 被证明是不同的隔间。这项研究将确定每个苍白条纹对 背侧和腹侧处理流。V2和V4包含视觉刺激的分离表示 方向和颜色。Aim3的目标是确定V2和V4之间的连接是否发生在 相似特征表示的区域，或是否在V4中发生跨流收敛。这项研究将 还提供了对前馈机制与区域内机制在V4 RF和 专题地图。这项拟议的研究具有重要意义，因为它将揭示解剖和功能连接 V1和V2输出通道的原则，将作为假设驱动和 对它们功能的解剖学限制的研究。拟议的研究具有创新性，因为它结合了 高分辨率标记单个轴突的功能成像，使用标记单个轴突的新方法 和重建。

PROJECT SUMMARY Understanding organizing principles for neural circuits in the cortex is necessary to understand their computational function. This principle has informed the new field of "connectomics", devoted to generating wiring diagrams of the brain, or subsections of it, at different scales. In the primate visual cortex, areas V1 and V2 distribute information they receive from the retina to virtually all higher areas, sorting this information into dorsal and ventral processing streams for spatial and object vision, respectively. The objective of this application is to uncover the rules of anatomical and functional connectivity for V1 and V2 output pathways, in order to understand how these areas may refine and re-organize retinal signals into visual processing streams, and how these pathways contribute to creating the complex receptive field (RF) properties of neurons in higher areas. Parallel pathways from V1 to V2 project to distinct cytochrome-oxidase stripes (thick, thin and pale). During the previous grant period, we discovered 4 segregated pathways between V1 & V2. We also discovered specialized functional organizations of V1 pathways related to thick and pale stripes that may underlie the responses of V2 RFs to angled and curved contours. This proposal builds upon these findings. The goal of Aim 1 is to understand how single V1 cells contribute to generating V2 RFs, by determining the axonal and dendritic layout of single V1 output cells over the V1 and V2 orientation maps. We will provide the fist comprehensive anatomical description at mesoscopic scale of V1 cells projecting to specific V2 stripes, including the intra-V1 and intra-V2 axonal arborizations of identified cell types, and their functional organization within both V1 & V2. This information will provide insights into the roles of feedforward vs. intra-V2 mechanisms in the generation of V2 RFs, and on the contribution of intra-V1 and V1-to-V2 circuits to the processing of contours. We will then investigate whether anatomical and functional segregation of the 4 pathways is maintained or lost downstream of V2. The goal of Aim2 is to determine the areal projections of the two V2 pale stripe types, which we have recently demonstrated to be distinct compartments. This study will determine each pale stripe contribution to the dorsal and ventral processing streams. V2 and V4 contain segregated representations for visual stimulus orientation and color. The goal of Aim3 is to determine whether connections between V2 & V4 occur between regions of similar featural representation, or whether cross-stream convergence occurs in V4. This study will also provide insights into the roles of feedforward vs. intra-areal mechanisms in the generation of V4 RFs and featural maps. The proposed research is significant because it will reveal anatomical and functional wiring principles for V1 and V2 output pahways that will serve as a foundation for hypothesis-driven and anatomically-constrained studies of their function. The proposed research is innovative because it combines functional imaging with high-resolution labeling of single axons, using novel methods for single axon labeling and reconstruction.