Role of neuronal ensembles in visual processing

项目摘要 视觉是人类最依赖的感官形式，以通过视觉导航。 建立有意义的社会关系。因此视觉系统的紊乱 往往导致严重的人际关系和经济困难。虽然取得了很大进展， 解剖了视网膜对光线产生动作电位的机制， 令人惊讶的是，我们对大脑如何解释和理解这些信息知之甚少。 信号.我建议利用尖端的光学技术来阐明神经元是如何 集合体（共同活动的细胞群）在初级视觉皮层（V1）中编码感觉信息， 新皮层区域需要执行认知要求高的任务， 歧视V1中的集合表现出可再现的空间和时间的活动模式 这些结构定义了皮层微电路的功能词汇， 与动物的视野和内部状态有关的信息。但是他又怎 这些计算出现，无论它们是否由独立的电路组成， 它们为视觉感知提供的模板仍然未知。解决这些 问题，我将进行慢性双光子全息钙成像的一致 清醒小鼠学习视觉引导任务的V1神经元群体。图像相同 纵向区域将使我们能够识别皮质集合如何出现或重塑， 视觉特征成为任务突出的（目标1）。然后，为了测试它们的功能作用，我将人工 用双光子全息光遗传学激活识别的神经集合，以测试是否 它们的活动足以产生视觉感受并引起预期的视觉诱发 响应（目标2）。这些实验的成功完成将测试神经系统是否 集合体确实是大脑皮层功能的基石， 感知和行为之间的联系。此外，本项目将展示 学习过程中皮层集合体如何整合视觉信息和非感觉变量 并将在更全面地理解视觉方面取得新的进展，这是 解决失明等疾病缺乏有效治疗选择的问题。

Project Summary Vision is the sensory modality that humans depend on most to navigate through the world and to establish meaningful social relationships. Disorders of the visual system therefore often lead to severe interpersonal and economic hardships. Although much progress has been made dissecting the retinal mechanisms that generate action potentials in response to light, surprisingly little is known about how the brain actually interprets and contextualizes these signals. I propose to leverage cutting-edge optical technologies to clarify how neuronal ensembles (coactive groups of cells) encode sensory information in primary visual cortex (V1), the neocortical region which is required to perform cognitively demanding tasks including visual discrimination. Ensembles in V1 exhibit activity patterns with reproducible spatial and temporal structures which define the functional vocabulary of cortical microcircuits and that likely carry information pertaining to both the visual field and to the internal state of the animal. Yet how these computations emerge, whether they are comprised of independent circuits, and the extent to which they provide a template for visual perception remain unknown. To address these questions, I will perform chronic two-photon holographic calcium imaging of a consistent population of V1 neurons in awake mice learning a visually-guided task. Imaging the same region longitudinally will allow us to identify how cortical ensembles emerge or are remodeled as visual features become task-salient (Aim 1). Then, to test their functional role, I will artificially activate identified neural ensembles with two-photon holographic optogenetics to test whether their activity is sufficient to generate a percept and to elicit the expected visually-evoked response (Aim 2). Successful completion of these experiments will test whether neural ensembles are indeed building blocks of cortical function and will provide a new understanding of the link between perception and behavior. Furthermore, the current project will demonstrate how cortical ensembles integrate visual information with non-sensory variables during learning and will yield new inroads towards a more complete understanding of vision, a prerequisite to addressing the paucity of effective treatments options for illnesses such as blindness.