FUNCTIONAL ORGANIZATION OF VISUAL CORTEX

视觉皮层的功能组织

• 批准号: 6635593
• 负责人: DAVID FITZPATRICK
• 金额: $ 34.65万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6635593
• 关键词: Scandentia; behavioral /social science research tag; brain mapping; cell type; developmental neurobiology; histology; intercellular connection; neural information processing; neuronal transport; single cell analysis; tissue /cell preparation; visual cortex; visual pathways; visual perception; visual stimulus

Neurons in visual cortex exhibit a remarkable selectivity for certain features of the visual stimulus--a selectivity that must reflect an underlying specificity in the organization of their synaptic connections. Much of the anatomical specificity in cortical circuitry depends on the precise arrangement of intracortical axon arbors. For example, intrinsic axon arbors are responsible for interconnecting selected subsets of neurons that reside in different cortical layers; they are also responsible for selectively linking columns of neurons that share similar response properties. The proposed experiments focus on another dimension of intrinsic axonal connections which, while less conspicuous, may be no less important: the arrangement of axonal connections with respect to the map of visual space. The goal is to determine whether specificity in the topographic arrangement of intracortical axons, like laminar and modular specificity, plays a role in shaping the visual responses of cortical neurons. Previous studies have shown that individual cortical neurons often give rise to axon arbors that are elongated across the cortical surface, extending farther and giving rise to more terminals along one axis of the map of visual space than along the others. A combination of anatomical and physiological methods will be used to: (1) examine the relaxation between this anisotropy in connections and the preference of cortical neurons for oriented edges and (2) examine how this anisotropy might contribute to the response properties of cortical neurons. These experiments should provide new insights into the rules that govern the organization of local circuits in visual cortex--information that is crucial for understanding the neural basis of visual perception.

视觉皮层中的神经元对视觉刺激的某些特征具有显着的选择性 - 这种选择性必须反映其突触连接组织中的潜在特异性。皮质回路中的许多解剖学特异性都取决于皮质内轴突轴的精确排列。例如，固有的轴突乔木负责互连位于不同皮层层中的神经元的选定子集。他们还负责选择性地连接共享相似响应属性的神经元列。提出的实验集中在固有的轴突连接的另一个维度上，尽管轴突连接较少，但它可能同样重要：轴突连接相对于视觉空间图的排列。目的是确定皮质内轴突的地形布置（如层流和模块化特异性）是否在塑造皮质神经元的视觉反应中起作用。先前的研究表明，单个皮质神经元通常会引起轴突乔木，这些神经元在皮质表面上伸长，延伸到更远的地方，并沿视觉空间图的一个轴沿着一个轴延伸到更多的末端。解剖学和生理方法的组合将用于：（1）检查这种各向异性之间的松弛与皮质神经元对定向边缘的偏好，以及（2）检查该各向异性如何有助于皮质神经元的反应特性。这些实验应提供有关管理视觉皮层本地电路的规则的新见解，这对于理解视觉感知的神经基础至关重要。