Processing and transformation of visual signals in the superior colliculus

项目摘要 了解视觉信息如何通过皮质和皮质下通路进行处理和转换 产生视觉引导行为是视觉研究的基础。作为一个关键的感觉运动中心， 哺乳动物中脑的上丘(SC)在一种背景下调节视觉引导行为-- 依赖的方式，并为理解神经原理的加工和 将视觉信号转换为适当的行为反应。SC的视觉感觉层(或 SCS)从视网膜直接接收自下而上的视觉信息，以及来自 其他视觉结构。SCS神经元如何整合来自不同来源的信息 对上下文相关的视觉信号的处理和转换的不同影响 行为控制在很大程度上仍然不清楚。在这个项目中，通过专注于视觉处理和 两种显著的SC介导的视觉引导行为、防御行为诱导下的转换 通过高场隐约的视觉刺激和低场移动点引起的走近行为，我们将 研究SC的两个主要输入，即来自初级视觉皮质(V1)的谷氨酸能输入是如何 腹侧膝状体(VLGN)的GABA能输入参与了SC的形成 正在处理。我们将测试一个重要的假设，即V1和vLGN输入共同作用于调节 SC神经元视觉特征的增益和选择性以实现对视觉的上下文相关调制 行为。在目标1中，我们将研究V1输入如何调制SCs神经元的视觉反应特性 以依赖于叶片的方式，以及它如何有助于选择防御反应 高场威胁性视觉刺激通过在SCs亚回路之间引起竞争性的相互作用。在……里面 目的2，我们将研究vLGN在调节SCs神经元对不同类型神经元反应中的功能作用。 视觉刺激及其在大小偏好的情境调节中的作用 行为。通过这些拟议的研究，我们希望能大大提高我们对功能的理解 组织、信号整合、细胞内/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.