Processing and transformation of visual signals in the superior colliculus

项目摘要 理解视觉信息是如何通过皮层和皮层下通路处理和转换的 产生视觉引导的行为是视觉研究的基础。作为一个重要的感觉运动中心， 哺乳动物中脑中的上级丘（SC）在一种环境中介导视觉引导行为， 依赖的方式，并持有很大的希望，了解神经原则的处理和 将视觉信号转化为适当的行为反应。SC的视觉感觉层（或 SC）接收来自视网膜的视觉信息的直接自下而上的中继，以及来自多个神经元的输入。 其他视觉结构。SC神经元如何整合来自不同来源的信息， 不同地影响视觉信号的处理和转换， 行为控制在很大程度上仍不清楚。在这个项目中，通过专注于视觉处理和 两个显著的SC介导的视觉引导行为，防御行为诱导的转化 通过高场隐现视觉刺激和低场运动点诱导的接近行为， 研究SC的两个主要输入，来自初级视皮层（V1）的听觉输入， 腹侧膝状体（vLGN）的GABA能输入参与SC的形成 处理.我们将测试一个总体假设，即V1和vLGN输入共同作用，以调节 获得和选择性的视觉功能的SC神经元，以实现上下文相关的调制的视觉 行为。在目的1中，我们将研究V1输入如何调节SC神经元的视觉反应特性 以及它如何有助于选择防御反应， 高场威胁视觉刺激，但引起SC子电路之间的竞争性相互作用。在 目的2，我们将研究vLGN输入在调节SC神经元对各种刺激的反应中的功能作用。 视觉刺激以及它如何在接近中大小偏好的上下文依赖调制中发挥作用 行为通过这些研究，我们希望能大大提高我们对功能性的理解， 组织，信号整合，内/层间相互作用以及功能调节， SC电路。

Project Summary Understanding how visual information is processed and transformed by cortical and subcortical pathways to generate visually guided behavior is fundamental for visual research. As a critical sensorimotor center, the superior colliculus (SC) in the mammalian midbrain mediates visually guided behaviors in a context- dependent manner and holds great promise for understanding neural principles for the processing and transformation of visual signals into appropriate behavioral responses. The visuosensory layer of SC (or SCs) receives direct bottom-up relay of visual information from the retina, as well as inputs from multiple other visual structures. How the information from different sources is integrated by SCs neurons to differentially influence the processing and transformation of visual signals for context-dependent behavioral control remains largely unclear. In this project, by focusing on visual processing and transformation underlying two salient SC-mediated visually guided behaviors, defense behavior induced by high-field looming visual stimuli and approach behavior induced by low-field moving dots, we will investigate how the two major inputs of SC, the glutamatergic input from the primary visual cortex (V1) and GABAergic input from the ventral geniculate nucleus (vLGN), contribute to the shaping of SC processing. We will test an overarching hypothesis that V1 and vLGN inputs act together to regulate the gain and selectivity of visual features of SC neurons to achieve context-dependent modulation of visual behaviors. In Aim 1, we will examine how V1 input modulate visual response properties of SCs neurons in a lamina-dependent manner and how it contributes to selection of defensive reactions in response to high-field threatening visual stimuli though eliciting competitive interactions between SCs subcircuits. In Aim 2, we will examine the functional role of vLGN input in modulating SCs neuron responses to various visual stimuli and how it plays a role in the context-dependent modulation of size preference in approach behavior. Though these proposed studies, we hope to greatly enhance our understanding of functional organization, signal integration, intracollicular/interlaminar interactions as well as functional modulation in SC circuits.