The interaction of cortical and subcortical processing in natural sensory behavior

摘要 我们的大脑已经进化到从丰富而复杂的自然环境中提取相关的感官信息， 以驱动适当的行为。多个大脑结构可以在这种处理中发挥作用，而 皮层在哺乳动物研究中通常是最突出的，许多行为也可以由上级皮层介导。 丘，特别是定向和回避反应显着的刺激。然而，大脑皮层的相对作用 和上级丘，以及它们之间的相互作用，知之甚少，因为这两个不是典型的 一起研究，特别是在自然行为背景下。在这里，我们将使用捕获猎物的鼠标， 一个行为学范式来研究皮层执行的计算，以及它们对SC的影响，跨越两个 感觉形式-视觉和听觉。根据我们的初步数据，我们假设大脑皮层 在复杂的感觉环境中需要灵活识别刺激的条件下是必要的， 而SC在简单条件下用作特定特征检测器。我们进一步假设，在这两个 在某些情况下，SC作为效应器定位猎物，皮层介导其在复杂环境中的作用 通过SC的自上而下调制。 为了测试潜在的机制，我们将首先确定皮层在感觉的不同方面的作用， 处理，通过在猎物捕获期间使初级感觉皮层（V1或A1）失活，在我们 从孤立的刺激到复杂的感官环境，改变任务的复杂性。我们接下来将确定 在这些不同的条件下，通过细胞外多位点记录在皮层和SC中编码的信息 在猎物捕获行为和头部固定的被动呈现刺激。最后，我们将确定 皮质和SC之间的相互作用，通过测量失活皮质丘投射对 所有这些实验将在视觉和听觉领域进行，以便 确定可用作皮质-丘系统中的规范计算的共享原则。 此外，该项目建立在共同PI Niell（视觉）在这些领域的互补专业知识的基础上 生理学）和Wehr（听觉生理学），他们有着悠久的合作历史，包括 发展了先前的猎物捕获模式。

Abstract Our brains have evolved to extract relevant sensory information from rich and complex natural environments in order to drive appropriate behavior. Multiple brain structures can play a role in such processing, and while cortex is often most prominent in mammalian studies, many behaviors can also be mediated by superior colliculus, particular orienting and avoidance responses to salient stimuli. However, the relative roles of cortex and superior colliculus, and the interactions between them, are poorly understood as the two are not typically studied together, particularly within a natural behavior context. Here we will use prey capture in the mouse as an ethological paradigm to study the computations performed by cortex, and their impact on SC, across two sensory modalities - visual and auditory. Based on our preliminary data, we hypothesize that cortex is necessary under conditions that require flexible identification of stimuli in complex sensory environments, whereas SC serves as a specific feature detector in simple conditions. We further hypothesize that in both cases, SC serves as the effector to orient towards prey, with cortex mediating its role in complex environments via top-down modulation of SC. In order to test potential mechanisms, we will first determine the role of cortex in different aspects of sensory processing, by inactivating primary sensory cortex (V1 or A1) during prey capture, under conditions where we vary the task complexity from isolated stimuli to complex sensory environments. We will next determine the information encoded in cortex and SC during these different conditions via extracellular multisite recordings during both prey capture behavior and head-fixed passive presentation of stimuli. Finally, we will determine the interaction between cortex and SC by measuring the impact of inactivating cortico-collicular projections on neural coding in SC. All these experiments will be performed in both visual and auditory domains in order to determine shared principles that may serve as canonical computations in the cortico-collicular system. Furthermore, this project builds on the complementary expertise in these domains of co-PIs Niell (visual physiology) and Wehr (auditory physiology), who have an established history of collaboration including developing the prey capture paradigm previously.