FUNCTIONAL PATHWAYS OF THE COCHLEAR NUCLEUS

耳蜗核的功能通路

• 批准号: 6379558
• 负责人: JOHN R DOUCET
• 金额: $ 8.18万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6379558
• 关键词: auditory nuclei; auditory pathways; brain mapping; cell type; electrophysiology; electrostimulus; histology; laboratory rat; neural information processing; neuronal transport; neurophysiology

Our long term goal is to understand the neural codes and computations that underlie hearing. All acoustic information is presented to the brain with the synapses formed by auditory nerve fibers in the cochlear nucleus. Here, the data contained in the nerve are distributed amongst a variety of cell types that each represent some feature of the acoustic environment. Cochlear nucleus neurons and their neural codes form the foundation of central auditory pathways that are ultimately responsible for our ability to locate and identify a sound: perceptions that collectively we refer to as hearing. How and where the neural computations that underlie these perceptions occur will depend on the axonal pathways engendered by distinct classes of cochlear nucleus neurons, and their synaptic organizations in the structures that they target. In this proposal, we plan to study the axonal pathways borne by one large group of cochlear nucleus neurons referred to as multipolar neurons. We propose that multipolar neurons in the ventral division of the cochlear nucleus play a key role in the initial stages of acoustic information processing. They are full participants in the intrinsic circuitry of the cochlear nucleus and their axons target every brain stem nucleus in the auditory pathway. Multipolar neurons are a heterogeneous population, suggesting that they are comprised of several distinct subclasses of cells. We propose to use retrograde pathway tracing methods to identify the targets of different populations of multipolar neurons, and electrophysiological recording techniques to match the axonal pathway of each type with its physiological response properties. These data will provide new knowledge with respect to the functional roles served by a large group of cochlear nucleus cells, as well as provide insights into the nature of the neural computations performed in central auditory nuclei.

我们的长期目标是了解听力背后的神经编码和计算。 所有声音信息都通过耳蜗核中的听觉神经纤维形成的突触呈现给大脑。 在这里，神经中包含的数据分布在各种细胞类型中，每种细胞类型代表声学环境的某些特征。 耳蜗核神经元及其神经编码构成了中枢听觉通路的基础，最终负责我们定位和识别声音的能力：我们统称为听觉的感知。 这些感知背后的神经计算如何以及在哪里发生，将取决于不同类别的耳蜗核神经元产生的轴突通路，以及它们在目标结构中的突触组织。 在这项提案中，我们计划研究一大群被称为多极神经元的耳蜗核神经元所承载的轴突通路。我们认为耳蜗核腹侧部分的多极神经元在声信息处理的初始阶段发挥着关键作用。 它们完全参与耳蜗核的内在回路，它们的轴突瞄准听觉通路中的每个脑干核。多极神经元是一个异质群体，表明它们由几个不同的细胞亚类组成。我们建议使用逆行通路追踪方法来识别不同多极神经元群的目标，并使用电生理记录技术将每种类型的轴突通路与其生理反应特性相匹配。这些数据将提供有关一大群耳蜗核细胞所发挥的功能作用的新知识，并提供对中枢听觉核团中执行的神经计算的性质的见解。