FUNCTIONAL MICRO-ORGANIZATION OF COLOR AND ORIENTATION IN PRIMARY VISUAL CORTEX

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 本研究的主要目的是了解初级视觉皮质(V1)第2/3层神经元的功能组织。我们正在研究具有明确反应属性的细胞的组织，既包括它们与细胞色素氧化酶斑点和定位图等较大隔间的关系，也包括它们的精细排列。过去对这些问题的研究有两种方法：电生理记录，它产生单个神经元的功能特征；以及内在信号成像，它提供了皮质功能图谱的概述，但分辨率很低(低于100米)。我们目前工作的关键方面是，我们正在使用一种新的方法，即双光子激光扫描显微镜钙成像，它弥合了单一单位电生理学和传统光学成像之间的差距。这项技术为我们提供了从给定皮质斑块中基本完整的细胞样本中提取单个细胞的分辨率，据我们所知，这是第一次将其用于研究灵长类动物的皮质微结构。 我们的初步结果揭示了一种耐人寻味的非常清楚的颜色选择细胞聚集成功能单位的现象，很可能与细胞色素氧化酶斑点有关。在这些颜色簇中，我们发现了更详细的组织，其中蓝色ON细胞与蓝色OFF细胞分开，并且蓝色/黄色细胞组排列成与红色/绿色细胞不同的群集。这些结果无法从早期的工作中预测到，它们为解决视觉生理学文献中一些长期存在的争论提供了一个框架。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The principal goal of this study is to understand the functional organization of neurons in layers 2/3 of primary visual cortex (V1). We are examining the organization of cells with defined response properties, both in their relation to larger compartments like cytochrome-oxidase blobs and orientation maps, as well as in their fine-scale arrangement. These issues have been studied in the past with two approaches: electrophysiological recordings, which yield functional characterizations of single neurons, and intrinsic signal imaging, which provides an overview of functional maps in cortex but with very low resolution (less than 100 m). The key aspect of our present work is that we are using a new approach, calcium imaging with two-photon laser-scanning microscopy, which bridges the gap between single-unit electrophysiology and conventional optical imaging. The technique gives us single cell resolution from an essentially complete sample of cells in a given patch of cortex, and, to our knowledge, this is the first time it has been used to study cortical microarchitecture in primates. Our initial results have revealed an intriguing and very clear clustering of color-selective cells into functional units, most likely related to cytochrome-oxidase blobs. Within these color clusters we find an even more detailed organization, with blue ON cells segregated from blue OFF cells, and with groups of blue/yellow cells arranged in clusters distinct from red/green cells. These results could not have been predicted from earlier work, and they provide a framework for resolving some long-standing debates in the visual physiology literature.