Multisensory integration in the mouse superior colliculus

上丘(SC)在整合视觉和听觉输入以评估 突出重点，推动行动。然而，用于编码多模式的底层单元类型和电路 在发展过程中用来形成电路的信息和机制在很大程度上仍然是未知的。 最近老鼠遗传学的新技术的爆炸性发展使得神经元和电路可以被操控 和特定的基因被移除，但令人惊讶的是，小鼠还没有被证明是一个 研究感觉统合。本提案的总体目标是确定 小鼠SC中的视觉/听觉多感觉神经元，以确定这些特性如何在 小鼠品系经过基因工程改造，以测试关于这些特性如何发展的假说。中环 有待检验的假设是，视觉和听觉信息在小鼠SC中汇聚，以创建 形成空间的多模式地图的多模式神经元，以及使用视觉地图形成的地图对齐 模板匹配机制。 特定目标1的目标是识别和确定小鼠SC的响应特性 视觉/听觉多模式神经元。为了做到这一点，清醒的、头部固定的老鼠，允许它们在 跑步机，将受到空间/时间/光谱受限的视觉和听觉刺激，而 使用高密度硅探针记录SC神经元的反应特性。SC神经 使用高密度硅，将同时记录每只小鼠体内~170个神经元的活动 探测器。数据分析将确定视觉、听觉和视觉的时空接受场 视觉/听觉多模式神经元及其感觉整合特性，以及空间/时间/光谱 促进一体化所需的刺激措施的组成部分。创新包括使用虚拟听觉空间 提供局部化声音的刺激，以及使用的录音和数据分析方法。 特定目标2中提出的实验将检验长期存在的假设，即对齐和 使用视觉地图作为模板，将视觉和听觉输入整合到SC表格中。这个 方法是记录和分析目标1中的听觉和视觉反应特性，但不同于 转基因小鼠在SC中有一个复制的视觉映射，并确定听觉映射是否 重新排列以对齐复制的可视地图并与其集成。 这项拟议的研究具有重要意义，因为它将提供对接受者的第一个全面分析 小鼠SC内视觉/听觉整合神经元的场特性，并将决定一般 这些特性如何发展的原理。这项工作的成果可以立即利用，并在 未来，为了确定用于整合感觉信息的潜在电路，特定的细胞类型 以及动物的状态如何调节这些特性。

The superior colliculus (SC) plays a critical role in integrating visual and auditory inputs to assess saliency and promote action. However, the underlying cell types and circuitry used to encode multimodal information and the mechanisms used during development to form the circuitry remain largely unknown. The recent explosion of new technology in mouse genetics allows neurons and circuits to be manipulated and specific genes to be removed, but surprisingly, the mouse has not yet been shown to be a model to study sensory integration. The overall objective of this proposal is to determine the functional properties of visual/auditory multisensory neurons in the mouse SC, to determine how these properties change in a mouse line genetically engineered to test hypotheses about how these properties develop. The central hypothesis to be tested is that visual and auditory information converge in the mouse SC to create multimodal neurons that form a multimodal map of space, and that map alignment forms using a visual map template-matching mechanism. The goal of Specific Aim 1 is to identify, and determine the response properties of, mouse SC visual/auditory multimodal neurons. To accomplish this, awake, head-fixed mice, allowed to freely run on a treadmill, will be stimulated with spatially/temporally/spectrally restricted visual and auditory stimuli while the SC neuronal response properties are being recorded using high-density silicon probes. The SC neural activity of ~170 neurons will be simultaneously recorded from in each mouse, using high-density silicon probes. Data analysis will determine the spatiotemporal receptive fields of the visual, auditory and visual/auditory multimodal neurons, their sensory integration properties, and the spatial/temporal/spectral components of the stimulus needed to elicit integration. Innovations include the use of virtual auditory space stimuli to present localized sound, and the recording and data analysis methods used. Experiments proposed in Specific Aim 2 will test the longstanding hypothesis that the alignment and integration of the visual and auditory inputs in the SC form using the visual map as a template. The approach will be to record and analyze the auditory and visual response properties as in Aim 1 but from transgenic mice engineered to have a duplicated visual map in the SC, and determine if the auditory map rearranges to align and integrate with the duplicated visual map. The proposed research is significant because it will provide the first comprehensive analysis of the receptive field properties of visual/auditory integrative neurons in the mouse SC, and will determine the general principles of how these properties develop. The results of this work can be exploited immediately and in the future, to determine the underlying circuitry used to integrate sensory information, the specific cell types involved, and how the state of the animal modulates these properties.