Coding of Auditory Space in the Avian Brain

鸟类大脑听觉空间的编码

• 批准号: 6962938
• 负责人: Jose L Pena
• 金额: $ 37.16万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6962938
• 关键词: auditory cortex; auditory stimulus; binaural hearing; biophysics; computational biology; confocal scanning microscopy; electrophysiology; electrostimulus; neuroanatomy; neurophysiology; owls; sound perception; thalamus

DESCRIPTION (provided by applicant): Barn owls offer several advantages for the study of sound localization, including behavioral, neurophysiological and anatomical information about the localization cues they use. For the owls, the interaural time difference (ITD) encodes the horizontal angle and the interaural level difference (ILD) encodes the vertical angle of sound direction. The main goal of the present proposal is to fill the gaps in our knowledge about the processing of ITD and ILD by using new ideas and methods. The owl's brain processes ITD and ILD in separate pathways. All these processes are organized to produce the sensitivity for combinations of ITD and ILD in space-specific neurons. The nucleus laminaris is the first site of ITD detection. It detects ITDs in separate frequency bands in which each neuron is tuned to a narrow range of frequencies. Our preliminary results show that we can predict the frequency tuning curve of a laminaris neuron from its responses to ITDs, because the neuron simply adds ITD responses for different frequencies. This finding indicates that laminaris neurons carry out cross-correlation of inputs from the two sides. We plan to extend this analysis to high-order ITD sensitive neurons to determine the stage where the additive process is replaced by non-linear integration of inputs from different frequency bands. We already know that the ITD and ILD combination sensitivity of neurons of the external nucleus of the inferior colliculus (ICx) involves a multiplication of postsynaptic potentials from the ITD and ILD pathways. We plan to determine the biophysical bases for multiplication. ICx projects mainly to the optic tectum but not to the thalamus so far as we know. However, both the thalamus and forebrain contain space-specific neurons. The question is how two independent brain areas come to contain neurons with the same response properties. Our preliminary results suggest that the thalamic-forebrain space-specific neurons are different from the ICx counterparts. We propose to pursue this line of research further in this proposal.

描述（由申请人提供）：谷仓猫头鹰为声音定位研究提供了多种优势，包括有关它们使用的定位线索的行为、神经生理学和解剖学信息。对于猫头鹰来说，耳间时间差（ITD）编码水平角，耳间电平差（ILD）编码声音方向的垂直角。本提案的主要目标是通过使用新的想法和方法来填补我们在 ITD 和 ILD 处理方面的知识空白。猫头鹰的大脑以不同的途径处理 ITD 和 ILD。所有这些过程都经过组织，以在空间特异性神经元中产生对 ITD 和 ILD 组合的敏感性。板层核是 ITD 检测的第一个部位。它检测不同频段中的 ITD，其中每个神经元都调谐到较窄的频率范围。我们的初步结果表明，我们可以根据板状神经元对 ITD 的响应来预测其频率调谐曲线，因为神经元只是将不同频率的 ITD 响应相加。这一发现表明层状神经元对两侧的输入进行互相关。我们计划将此分析扩展到高阶 ITD 敏感神经元，以确定加法过程被不同频段输入的非线性积分所取代的阶段。我们已经知道，下丘外核 (ICx) 神经元的 ITD 和 ILD 组合敏感性涉及 ITD 和 ILD 通路突触后电位的倍增。我们计划确定繁殖的生物物理基础。据我们所知，ICx 主要投射到视顶盖，但不投射到丘脑。然而，丘脑和前脑都含有空间特异性神经元。问题是两个独立的大脑区域如何包含具有相同反应特性的神经元。我们的初步结果表明丘脑前脑空间特异性神经元与 ICx 对应神经元不同。我们建议在本提案中进一步开展这方面的研究。