Development of Temporal Fine structure

颞精细结构的发育

• 批准号: 10182214
• 负责人: Catherine Emily Carr
• 金额: $ 31.09万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-05 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10182214
• 关键词: Address; Adrenergic alpha-Antagonists; Adult; Animal Model; Animals; Area; Auditory; Auditory system; Axon; Barn Owls; Bilateral; Binaural; Birds; Brain Stem; Cell Nucleus; Clinic; Cochlear Implants; Cochlear nucleus; Code; Conductive hearing loss; Data; Detection; Development; Discrimination; Ear; Environment; External auditory canal; Frequencies; Goals; Growth; Head; Hearing; Hearing Aids; Human; Impairment; Implant; Inhibitory Synapse; Iontophoresis; Knowledge; Language Development; Learning; Light; Location; Mammals; Maps; Measurement; Measures; Modeling; Modification; Myelin; Nature; Neurons; Nodal; Noise; Persons; Phase; Physiologic pulse; Physiological; Physiology; Population; Preparation; Process; Reproducibility; Research; Role; Signal Transduction; Sound Localization; Source; Speech Perception; Strigiformes; Structure; System; Testing; Thick; Time; Work; attenuation; binaural hearing; critical period; deafness; deprivation; early experience; experience; experimental study; extracellular; gamma-Aminobutyric Acid; implant design; in vivo evaluation; language perception; millisecond; myelination; nerve supply; new technology; normal hearing; programs; sound

PROJECT SUMMARY The broad goal of the proposed research program is to advance our understanding of sound localization. Even when a person has normal hearing, speech perception and learning in noisy reverberant environments may still be compromised due to persistently impaired binaural hearing capabilities. In more profound cases of deafness, bilateral cochlear implant users typically experience poor discrimination of interaural time differences (ITDs), potentially because of early deprivation. This proposal uses an avian model to advance our understanding of binaural development. We have developed this preparation to determine if/when there is a developmental window in which inputs from each ear are synchronized, in order for sensitivity to ITDs to develop. Sensitivity to binaural signals first appears in the brainstem and relies on sub-millisecond precision to detect ITDs. How such extreme precision comes about during development is not fully understood, and these birds provide a well understood model for measurement of precisely timed binaural signals. Our knowledge of this ITD circuit is detailed enough to test the following hypotheses about the physiology and development of sound localization circuits. In the broader context, understanding the mechanisms of sound localization should reveal common computational solutions to guide advances in hearing aid and cochlear implant design. The three overlapping areas to be investigated in this project are: 1. Determine if the representation of ITDs is plastic during development. Detection of ITDs depends on precise coding of delay, with current research on how ITDs change with head growth. We will use a unilateral conductive hearing loss (CHL) model, in which one ear canal is plugged around the onset of hearing, to induce experience dependent plasticity during the period of head growth. These experiments should allow us to determine if maps of ITD are modified by early experience. In Aim 1.2 we will focus on myelin plasticity as a potential mechanism for modification. 2. Address mechanisms underlying the emergence of temporal precision. If delays can be modified by altered experience, it is likely that normal ITD coding also shows developmental refinement. Delay lines encode time with sub-millisecond accuracy. To shed light on the mechanisms underlying ITD map formation, we will combine recordings of the extracellular field potential with intracellular recording from delay line axons to measure the development of ITD coding in the first 2 months posthatch. 3. The role of inhibition in the development of ITD coding. Given the importance of inhibition in regulating auditory brainstem activity, we will examine the nature of the inhibitory input to NL and cochlear nuclei. We will use the unilateral CHL model to induce experience dependent plasticity in map of ITD, and test the competing hypothesis to Aim 1.2, that changes in delay are correlated with changes in inhibition.

项目摘要 拟议的研究计划的广泛目标是促进我们对声音定位的理解。甚至 当一个人具有正常的听力时，在嘈杂的混响环境中的语音感知和学习可以 由于双耳听力能力持续受损，仍然会受到损害。在更深刻的情况下， 耳聋，双侧人工耳蜗使用者通常对耳间时间差的辨别力较差 （ITDs），可能是因为早期剥夺。该提案使用鸟类模型来推进我们的研究 了解双耳发育。我们已经开发了这种准备，以确定是否/何时存在 发育窗口，其中来自每个耳朵的输入是同步的，以便对ITD的敏感性 开发.对双耳信号的敏感性首先出现在脑干中，并依赖于亚毫秒的精度， 检测ITD。在开发过程中如何实现这种极端的精确度还没有完全理解， 鸟类为精确定时的双耳信号的测量提供了很好理解的模型。我们的知识 这个ITD回路足够详细，可以测试以下关于生理学和发育的假设。 声音定位电路在更广泛的背景下，理解声音定位的机制应该 揭示了常见的计算解决方案，以指导助听器和人工耳蜗设计的进步。的 该项目将调查的三个重叠领域是： 1.在开发过程中确定ITD的表示是否为塑料。 ITD的检测依赖于延迟的精确编码，目前的研究是ITD如何随头部变化 增长我们将使用单侧传导性听力损失（CHL）模型，其中一个耳道被堵塞 在听觉发生前后，诱导头部发育期间的经验依赖可塑性。 这些实验应该使我们能够确定ITD的地图是否被早期经验所修改。目标1.2 我们将集中讨论髓磷脂可塑性作为一种潜在的修饰机制。 2.解决时间精确性出现的潜在机制。 如果延迟可以通过改变经验来改变，那么正常的ITD编码也可能表现为发育性的， 精致。延迟线以亚毫秒的精度对时间进行编码。为了阐明 作为ITD图形成的基础，我们将联合收割机记录细胞外场电位与细胞内场电位相结合。 从延迟线轴突记录以测量接种后前2个月ITD编码的发展。 3.抑制在ITD编码发展中的作用。 考虑到抑制在调节听觉脑干活动中的重要性，我们将研究 对NL和耳蜗核的抑制性输入。我们将使用单侧CHL模型来归纳经验 ITD地图中的依赖可塑性，并测试目标1.2的竞争假设，即延迟的变化 与抑制的变化相关。