Neural Mechanisms of Sound Localization

声音定位的神经机制

• 批准号: 6990529
• 负责人: ZHONGMIN LU
• 金额: $ 23.48万
• 依托单位: UNIVERSITY OF MIAMI CORAL GABLES
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6990529
• 关键词: Neural; Mechanisms; Sound; Localization

DESCRIPTION (provided by applicant): The long-term goal of the PI's research is to understand neural mechanisms of sound localization in vertebrates, including humans. The primary goal of this proposal is to determine how the primitive authority system of fish functions in sound localization. The PI's previous studies and others have demonstrated that fish determine the axis at which a sound wave is propagating by using arrays of spatially oriented sensory hair cells in the ear. However, it is not known how the brain processes the peripherally coded directional information in order to extract the specific direction of the sound. The proposed work will elucidate mechanisms underlying central auditory processing of directional information. It has been proposed that the fish ear is stimulated by a sound wave through two distinct pathways: direct particle motion input and indirect pressure input via the swim bladder. It was hypothesized that fish (with a swim bladder) first determine the axis on which the sound is propagating and then determine its direction by comparing the timings of inputs carrying pressure and particle motion information within the brain. The PI will test the two steps of this hypothesis on two functionally distinguishable teleost fishes, the sleeper goby and goldfish. Specific aims address anatomical organization and functional processing of directional information in the medulla and midbrain: 1) Auditory nuclei responsible for directional coding. Experiments will be carried out to reveal central projection sites of the saccular, lagenar, and utricular nerves and medullary projection sites in the midbrain using both anterograde and retrograde labeling methods. 2) 3D structure and cytoarchitecture of the auditory nuclei. Combined with the neuronal tracing, boundaries of the auditory nuclei will be defined to create their three dimensional structures using Neurolucida. Golgi stain studies will characterize types, sizes, and orientations of the auditory neurons. 3) Brain representation of the peripheral map of directional coding. Using whole-cell filling of Neurobiotin and confocal imaging, a 3D map of peripheral directional coding will be reconstructed to reveal how the saccular map of directional coding is represented in the medulla. 4) Directional response properties of auditory medullary and midbrain neurons. Single-cell recording and filling will characterize directional response properties, locations, and morphologies of auditory medullary and midbrain neurons to form a neural map(s) of best response axes of the neurons. 5) Differential-phase sensitive neurons. Single-cell recording will determine if there are neurons in the medulla and/or midbrain of the goldfish that encode specific timing differences between particle motion and pressure inputs

描述（由申请人提供）：PI研究的长期目标是了解包括人类在内的脊椎动物中声音定位的神经机制。该提案的主要目标是确定鱼类的原始授权系统如何在声音定位中起作用。 PI先前的研究以及其他研究表明，通过使用耳朵中的空间导向的感觉毛细胞来确定声波在传播的轴。但是，尚不清楚大脑如何处理外围编码的方向信息以提取声音的特定方向。拟议的工作将阐明定向信息中央听觉处理的基础机制。已经提出，通过两种不同的途径，声波刺激了鱼耳：直接粒子运动输入和间接压力输入通过游泳膀胱输入。假设鱼（带有游泳膀胱）首先确定声音传播的轴，然后通过比较大脑内携带压力和颗粒运动信息的输入时间来确定其方向。 PI将在两个在功能上可区分的硬骨鱼，卧铺的Goby和Goldfish上测试该假设的两个步骤。具体目的解决了髓质和中脑中定向信息的解剖组织和功能处理：1）负责方向编码的听觉核。实验将进行实验，以揭示使用顺序和逆行标记方法的中脑中牙周，拉格纳尔和痛苦神经的中央投影位点以及中脑中的髓质投影位点。 2）听觉核的3D结构和细胞结构。结合神经元跟踪，将定义听觉核的边界，以使用Neurolucida创建其三维结构。高尔基染色研究将表征听觉神经元的类型，大小和方向。 3）方向编码的周围图的大脑表示。使用神经蛋白和共聚焦成像的全细胞填充，将重建外围方向编码的3D图，以揭示髓质中定向编码的accular映射。 4）听觉髓质和中脑神经元的定向响应特性。单细胞记录和填充将表征听觉髓质和中脑神经元的定向响应特性，位置和形态，以形成神经元最佳响应轴的神经图。 5）差分相敏感的神经元。单细胞记录将确定金鱼的髓质和/或中脑中是否有神经元编码粒子运动和压力输入之间的特定时间差异