Role of cortical interneurons in visual perception

项目摘要 在哺乳动物的新大脑皮层，感觉刺激唤起高度结构化的神经活动模式。如何分组 具有特定神经活动模式的神经元编码信息是一个仍然是最前沿的问题 系统神经科学。具有相似反应特性的细胞之间的经常性联系被提出为 放大刺激特征并作为神经集合的构建块，但竞争集合如何 编码不同的刺激特征相互作用以形成单个连贯的感知是未知的。在.的情况下 视觉、自然视觉场景通常由代表对象或 视觉场景的背景，每个场景都让人联想到相互竞争和重叠的整体。因此，a 大脑的基本计算问题是从背景中解析显著特征 视觉场景。大脑皮层回路必须能够快速确定与主要图形相关的特征 并放大编码这些特征的表示的系综。这项提议的总体假设是 这种由表达生长抑素的中间神经元介导的点赞抑制抑制了竞争 组合以放大编码独特刺激特征的组合。我对这些机制的假设是错误的 规范的皮质计算，如环绕抑制，以及视觉感知现象，如 形体背景的种族隔离。为了验证这一假设，这项研究使用了体内全息图像的组合 光遗传学、双光子钙成像和行为分析，以努力了解其机制 潜藏在感知的神经基础之下。本项目的具体目标是独立检查电路 环绕抑制定向选择性的基础和检验这些回路是否为神经关联 小鼠初级视皮层图形-背景知觉的变化。总而言之，这些实验将测试 关于知觉所涉及的神经回路的性质以及知觉是如何的更基本的概念 在大脑中表现出来。因此，这一建议将为理解精神病学和 尚未获得机械学理解和医学治疗的神经系统疾病。

Project Summary In mammalian neocortex, sensory stimulation evokes highly structured patterns of neural activity. How groups of neurons with specific patterns of neural activity encode information is a question remaining at the forefront of systems neuroscience. Recurrent connections between cells with similar response properties are proposed to amplify stimulus features and serve as building blocks of neural ensembles, but how competing ensembles encoding different stimulus features interact to form a single coherent percept is unknown. In the case of vision, natural visual scenes are often comprised of multiple stimulus features that represent the subject or the background of a visual scene, each of which evoke competing and overlapping ensembles. Therefore, a fundamental computational problem for the brain is the parsing of salient features from the background of a visual scene. Cortical circuits must be able to quickly determine features that correlate to the primary figure and amplify ensembles encoding representation of those features. The overall hypothesis of this proposal is that like-to-like inhibition, mediated by somatostatin-expressing interneurons, suppresses competing ensembles to amplify ensembles encoding unique stimulus features. I hypothesize these mechanisms underly canonical cortical computations, such as surround suppression, as well as visual perceptual phenomena, such as figure-ground segregation. To test this hypothesis, this study uses a combination of in vivo holographic optogenetics, 2-photon calcium imaging, and behavioral assays in an effort to understand the mechanisms underlying the neural basis of perception. The specific aims of this project independently examine the circuit basis of orientation selectivity of surround suppression and tests whether these circuits are a neural correlate of figure-ground perception in mouse primary visual cortex. Taken together, these experiments will test the more fundamental ideas of the nature of neural circuits involved in perception and how percepts are represented in the brain. This proposal will therefore provide a basis for understanding psychiatric and neurological diseases that have yet eluded mechanistic understanding and medical treatment.