CRCNS: The balance of excitation and inhibition in sensory cortex

CRCNS：感觉皮层兴奋和抑制的平衡

• 批准号: 8932697
• 负责人: Nicholas J Priebe
• 金额: $ 18.93万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8932697
• 关键词: Accounting; Address; Affect; Afferent Neurons; American; Animals; Biology; Brain; Cells; Collaborations; Complex; Computer Simulation; Country; Data; Dependence; Educational process of instructing; Engineering; Environment; Equilibrium; Europe; European; Exhibits; Felis catus; France; General Population; Generations; Goals; Home environment; International; Light; Link; Location; Maps; Measures; Microscopy; Modeling; Mus; Nature; Neurons; Pattern; Physics; Postdoctoral Fellow; Primates; Property; Recurrence; Research; Rodent; Scheme; Science; Scientist; Sensory Process; Side; Site; Specificity; Students; Synapses; System; Testing; Thalamic structure; Training; United States; V1 neuron; Visit; Visual; Visual Cortex; Work; base; computer studies; critical period; equilibration disorder; experience; mouse model; network models; orientation selectivity; preference; receptive field; research study; response; sensory cortex; theories; two-photon; visual information; visual stimulus; web site; Accounting; Address; Affect; Afferent Neurons; American; Animals; Biology; Brain; Cells; Collaborations; Complex; Computer Simulation; Country; Data; Dependence; Educational process of instructing; Engineering; Environment; Equilibrium; Europe; European; Exhibits; Felis catus; France; General Population; Generations; Goals; Home environment; International; Light; Link; Location; Maps; Measures; Microscopy; Modeling; Mus; Nature; Neurons; Pattern; Physics; Postdoctoral Fellow; Primates; Property; Recurrence; Research; Rodent; Scheme; Science; Scientist; Sensory Process; Side; Site; Specificity; Students; Synapses; System; Testing; Thalamic structure; Training; United States; V1 neuron; Visit; Visual; Visual Cortex; Work; base; computer studies; critical period; equilibration disorder; experience; mouse model; network models; orientation selectivity; preference; receptive field; research study; response; sensory cortex; theories; two-photon; visual information; visual stimulus; web site

DESCRIPTION (provided by applicant): Visual cortex (V1) is the site at which dramatic transformations in neuronal receptive field properties - and thus the representation of the visual world - occur. One of the major transformations is the emergence of orientation selectivity. The functional organization of orientation selectivity in V1, however, takes different forms across species. In primates and carnivores it is topographically organized across cortex but in rodents no apparent organization is observed, yet rodents still exhibit orientation selectivity. Models tha describe the emergence of orientation selectivity have relied on the functional organization found in primates to guide connectivity between neurons that share selectivity. Two different hypotheses have been proposed to explain the emergence of orientation selectivity without functional organization in rodent V1. In one hypothesis, a specific synaptic connectivity between neurons with shared orientation preference may nonetheless exist without topographic organization of cortex. Alternatively, a computational study has now demonstrated that orientation selectivity may arise from non-specific network connectivity, with the constraint that the excitatory and inhibitory inputs are balanced ("balanced network model"). These two hypotheses are not mutually exclusive, and evidence for both hypotheses currently exists, but the degree to which each of these hypotheses reflects the actual connectivity underlying orientation selectivity in rodent V1 is unclear. The goal of our proposal is to address the relativ contributions of the balanced network and specific cortical connectivity to the generation of V1 orientation selectivity using experimental and computational studies. The proposed research is divided into three Specific Aims that will be carried out collaboratively and will integrate theory and experiment. Aim 1: What is the nature of the LGN input into layer 4 of V1 and how does layer 4 transform this input? In species with an orientation map, the LGN neurons afferent inputs are precisely arranged. Is this also true for species without an orientation map, and how does subcortical selectivity impact cortical selectivity? Can we explain the mechanism for orientation selectivity using a balanced network? Aim 2: Is the cortical connectivity specific? If V1 operates in the balanced state, strong orientation selectivity will arise in layer 2/3, whether or not the connectivity is feature dependet. We will measure the orientation dependence of input correlations and integrate any specific connectivity into a balanced model. Aim 3: How does disturbing the balanced state affect the cortical response? Our hypothesis is that the V1 operates in balanced excitation and inhibition regime. Perturbing this balance will be investigated theoretically and experimentally. Despite decades of study as the prime example of sensory processing, how V1 transforms incoming visual information is not well understood. It is not clear for example, whether feature specific connectivity is required to perform its function. I species with an orientation map, feature specific connectivity is not easily distinguished from connectivity that is solely dependent on anatomical distance because the anatomical and functional maps are linked. The lack of an anatomical organization for orientation selectivity in rodent V1 therefore presents us with an opportunity to study circuitry in a system in which the functional selectivities of neurons are independent of their location within the cortical network. Our proposal represents an integrative collaboration between theoreticians and experimentalists that will create an environment for students and postdoctoral fellows from different background to work side-by-side, gaining access to distinct expertise and perspectives. The collaboration represents a major effort for scientists to work in partnership between France and the US. This partnership will provide students from both France and the US the opportunity to participate in science outside of their home country. The proposed computational and experimental lab work is ideal for the training of students and postdoctoral fellows with backgrounds in physics, engineering or biology. It will be an excellent opportunity for theorists t see and participate in experiments, and for experimentalists to explore a theoretical perspective.

描述（由申请人提供）：视觉皮层（V1）是在神经元接受场特性中发生剧烈转换的站点，因此发生了视觉世界的表示。主要转变之一是方向选择性的出现。然而，V1中定向选择性的功能组织在各种物种之间采取不同的形式。在灵长类动物和食肉动物中，它是跨皮质的地形组织的，但是在啮齿动物中，没有观察到明显的组织，但啮齿动物仍然表现出定向选择性。模型描述了方向选择性的出现依赖于灵长类动物中发现的功能组织，以指导共享选择性的神经元之间的连通性。已经提出了两个不同的假设来解释在啮齿动物V1中没有功能组织的方向选择性的出现。在一个假设中，如果没有皮质的地形组织，则可能存在具有共同取向偏好的神经元之间的特定突触连通性。另外，一项计算研究现在表明，方向选择性可能来自非特异性网络连接性，并限制了兴奋性和抑制性输入是平衡的（“平衡网络模型”）。这两个假设不是相互排斥的，并且目前存在两个假设的证据，但是这些假设中的每一个都反映了啮齿动物V1中的实际连通性选择性的实际连接性。我们建议的目的是通过实验和计算研究来解决平衡网络的相对贡献以及对V1方向选择性产生的特定皮质连通性的贡献。拟议的研究分为三个特定目标，这些目标将进行协作，并将整合理论 和实验。 AIM 1：LGN输入到V1的第4层中的性质是什么？第4层如何转换此输入？在具有方向图的物种中，LGN神经元传入的输入精确布置。对于没有方向图的物种也是如此，皮层选择性如何影响皮层选择性？我们可以使用平衡网络解释定向选择性的机制吗？ 目标2：皮质连通性特定于皮质连接性吗？如果V1在平衡状态下运行，则在第2/3层中会出现强方向选择性，无论连接性是否为特征依赖性。我们将测量输入相关性的方向依赖性，并将任何特定的连接整合到平衡的模型中。 目标3：干扰平衡状态如何影响皮质反应？我们的假设是V1以平衡的激发和抑制状态运行。扰动这种平衡将在理论上和实验中进行研究。尽管研究是感觉处理的主要例子，但V1如何转化传入的视觉信息并未得到充分理解。例如，是否需要特定特定连接才能执行其功能。具有方向图的I物种，特征特定的连通性不容易与仅取决于解剖距离的连通性区分开，因为解剖图和功能图是连接的。因此，缺乏用于啮齿动物V1方向选择性的解剖组织，这使我们有机会在一个系统中研究电路的机会，在该系统中，神经元的功能选择性与其在皮质网络中的位置无关。 我们的建议代表了理论家和实验家之间的综合合作，该合作将为从不同背景到并排工作的学生和博士后研究员创造一个环境，从而获得了独特的专业知识和观点。该协作代表了科学家在法国与美国之间合作伙伴关系的主要努力。这种合作伙伴关系将为来自法国和美国的学生提供机会参加本国以外的科学。拟议的计算和实验实验室工作非常适合培训具有物理，工程或生物学背景的学生和博士后研究员。对于理论家来说，这将是一个绝佳的机会，参与实验，并为实验者探索理论观点。