Dynamics of Central Auditory Processing

中枢听觉处理的动力学

• 批准号: 6584100
• 负责人: JEREMY M SMALLING
• 金额: $ 2.77万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2007-01-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6584100
• 关键词: Chiroptera; GABA receptor; auditory feedback; auditory stimulus; electrical potential; electronic recording system; glycine receptors; histochemistry /cytochemistry; inferior colliculus; membrane potentials; neural conduction; neurons; neurophysiology; neurotransmitter antagonist; sound frequency; sound perception; stimulus interval

Prey identification by echolocating bats relies upon short term integration of the frequency modulations created by an insect's beating wings across echoes. Behavioral studies have shown that bats actively increase their sonar emission rate from low to high as they approach potential prey. Recent studies in the inferior colliculus (IC) have shown that this increase in rate results in a narrowing of amplitude response bandwidth; presumably increasing the amplitude resolution of the system. A fundamental question is how the stimulation rate (SR) affects the processing of other aspects of sound, including frequency. Therefore, two specific aims will be addressed. Aim 1 will test the influence of SR on the frequency response properties of IC units. We will compare single unit responses to sound stimuli at low and high SRs. Additionally, we will examine the minimum number of pulses necessary to generate rate-dependent changes in frequency selectivity. Aim 2 will study the influence of inhibition in the rate-dependent changes via iontophoretic application of GABAa and glycine receptor antagonists, thereby testing the hypothesis that an increased efficacy of inhibition at higher rates produces the rate-dependent sharpening of frequency selectivity.

蝙蝠通过回声定位来识别猎物依赖于昆虫拍打翅膀穿过回声产生的频率调制的短期积分。行为研究表明，当蝙蝠接近潜在猎物时，它们的声纳发射率会主动从低到高增加。 最近对下丘 (IC) 的研究表明，速率的增加会导致幅度响应带宽变窄；可能会增加系统的幅度分辨率。 一个基本问题是刺激率 (SR) 如何影响声音其他方面的处理，包括频率。因此，将解决两个具体目标。 目标 1 将测试 SR 对 IC 单元的频率响应特性的影响。 我们将比较低 SR 和高 SR 下单个单元对声音刺激的反应。 此外，我们将检查产生频率选择性的速率相关变化所需的最小脉冲数。目标 2 将通过 GABAa 和甘氨酸受体拮抗剂的离子电渗应用来研究抑制对速率依赖性变化的影响，从而检验以下假设：较高速率下抑制功效的增加会导致频率选择性的速率依赖性锐化。