Role of cortical interneurons in visual perception

项目摘要 在哺乳动物的新皮层中，感觉刺激引起高度结构化的神经活动模式。群体如何 具有特定神经活动模式的神经元编码信息是一个悬而未决的问题， 系统神经科学提出了具有相似响应特性的细胞之间的递归连接， 放大刺激特征，并作为神经集合的构建块，但竞争集合 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。的情况下 视觉，自然视觉场景通常由代表主体或主体的多个刺激特征组成。 视觉场景的背景，每一个都唤起竞争和重叠的整体。因此 大脑的基本计算问题是从背景中解析出显著特征。 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 并放大这些特征的集合编码表示。这一提议的总体假设是 由表达生长抑素的中间神经元介导的同类抑制， 集合以放大编码独特刺激特征的集合。我假设这些机制 典型的皮层计算，如环绕抑制，以及视觉感知现象，如 作为图形背景隔离。为了验证这一假设，这项研究使用了体内全息组合， 光遗传学、双光子钙成像和行为分析，以了解其机制。 感知的神经基础。该项目的具体目标是独立检查电路 环绕抑制的方向选择性的基础，并测试这些回路是否是神经相关的 在小鼠初级视觉皮层中的图形-背景感知。综合起来，这些实验将测试 更基本的概念，涉及感知的神经回路的性质，以及感知是如何 在大脑中表现出来。因此，这一建议将为理解精神病和 神经系统疾病，尚未逃避机械的理解和医学治疗。

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.