Visual Stimulus Coding and Metabolic Demand in Macaque Primary Visual Cortex

项目总结/摘要 神经反应特性、其解剖学基础和神经元之间的关系， 神经组织的代谢谱是定义神经系统正常功能结构的关键问题。 大脑皮层了解这些不同的系统是如何组织和协同工作的， 神经科学研究的基础脑活动光学成像的最新进展 使得同时记录神经元和代谢动力学的活动成为可能。 在灵长类初级视皮层（V1），神经元的方向和颜色之间的关系， 选择性与代谢酶细胞色素氧化酶（CO）的分布有关， 血管动力学猕猴V1的CO分布模式是该脑的定义特征 区在V1中，代谢需求局部和逐层变化，弥漫性CO密集斑块即可证明这一点 皮质被2/3层中密度较低的CO区域包围。CO在神经元中的分布也已被证实。 显示与供应皮质组织的脉管系统的密度和组织有关 营养和代谢物。 关于这些系统如何相互作用的长期观点表明， 神经元仅存在于CO斑块间区域，而未定向的颜色调谐神经元仅存在于 CO贴片。然而，最近的研究表明，这种功能隔离是不可能的。因为 早期的技术未能测量同一细胞中的视锥特异性和定向特异性反应 并将它们与CO模式联系起来，需要新的技术--如双光子成像--来开发一种 V1的功能组织的准确图片。此外，周围的脉管系统也被调节， 神经元已经被证明通过血管扩张和收缩的变化有自己的调节， 因此，如果神经对特定刺激的敏感性局部地 在V1中。 这个建议的目标是表征神经元视觉刺激调谐，CO 室身份，和血管动力学在灵长类动物V1。在目标1中，我们将使用多光子钙 成像以记录V1中的取向和视锥特异性选择性，并将成像区域与 CO染色的组织切片，以确定具有不同反应谱的神经元是如何 分布于CO斑块或斑块间区域。在目标2中，我们将研究血管动力学是否 与锥特定取向选择性和CO隔室身份有关。这项研究的结果 研究将为我们提供有关V1基本组织的全面信息，并从根本上改变 我们对视觉处理的理解。

Project Summary/Abstract The relationships between neural response properties, their anatomical underpinnings, and the metabolic profile of neural tissue are key issues that define the normal functional architecture of the cerebral cortex. Understanding how these different systems are organized and work together is fundamental to neuroscientific research. Recent advances in optical imaging of cerebral activity have made it possible to record activity of both neuronal and metabolic dynamics simultaneously. In primate primary visual cortex (V1), the relationships between neuronal orientation and color selectivity have been related to distribution of the metabolic enzyme cytochrome oxidase (CO) and vascular dynamics. The pattern of CO distribution in macaque V1 is a defining characteristic of this brain area. In V1, metabolic demand varies locally and by layer, as evident by diffuse CO-dense patches of cortex surrounded by less dense CO regions in layer 2/3. The distribution of CO in neurons has also been shown to be related to the density and organization of the vasculature which supplies the cortical tissue with nutrients and metabolites. The long-established idea of how these systems interact suggests that strongly orientation tuned neurons reside in only CO interpatch regions while unoriented color tuned neurons reside exclusively in CO patches. However, recent research has shown that such a functional segregation is unlikely. Because earlier techniques failed to measure cone-specific and orientation-specific responses in the same cells and relate them to the CO pattern, new techniques—such as 2-photon imaging—are needed to develop an accurate picture of the functional organization of V1. In addition, the vasculature surrounding tuned neurons has been shown to have its own tuning through changes in vessel dilation and contraction, and therefore are expected to be related to the CO pattern if neural sensitivity to specific stimuli is locally organized in V1. The goal of this proposal is to characterize the interaction of neuronal visual stimulus tuning, CO compartment identity, and vascular dynamics in primate V1. In Aim 1 we will use multiphoton calcium imaging to record orientation and cone specific selectivity in V1 and align the imaged regions with histological sections of CO staining to determine how neurons with different response profiles are distributed among CO patch or interpatch regions. In Aim 2 we will examine whether vascular dynamics are related to cone-specific orientation selectivity and CO compartment identity. The findings of this study will give us comprehensive information on the basic organization of the V1 and fundamentally alter our understand of visual processing.