AUDITORY NEUROBIOLOGY AND BIOPHYSICS

听觉神经生物学和生物物理学

• 批准号: 3216676
• 负责人: DUCK O KIM
• 金额: $ 19.33万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3216676
• 关键词: acoustic nerve; auditory discrimination; auditory nuclei; auditory pathways; auditory stimulus; biological models; cats; cell membrane; cell population study; computer simulation; model design /development; neurons; neurophysiology; noise; psychoacoustics; sound frequency

The long-term objective of this research is to advance our understanding of neural mechanisms underlying the encoding and processing of acoustic signals in the caudal parts of the auditory pathways, i.e., the auditory nerve (AN) and the cochlear nucleus (CN). Our specific aims are: (1) to investigate neural basis for behavioral intensity discrimination for pure tones presented in quiet and in masking noise by examining spatial profiles of discriminability measure d(e) defined in the manner of psychophysical signal detection theory, of various spontaneous rate (SR) populations of AN fibers; (2) to investigate neural basis of AN populations for behavioral frequency discrimination for pure tones by examining spatial profiles of discriminability measure d(e) in a manner similar to the above intensity discrimination study; (3) to conduct population studies of responses of AN fibers and several classes of CN neurons to complex signals (vowels and consonant-vowel syllables) presented in quiet and in masking noise and to delineate the transformations of spectro-temporally complex signal representation taking place between the AN and each of several classes of CN neurons; (4) to investigate CN neurons' behaviors of encoding amplitude-modulated tones in quiet and in masking noise and to compare them with those of AN fibers; distinct behaviors of "chopper" subclass neurons and "pause-build" neurons will be elucidated and they will be compared with predictions of CN neuronal models; (5) to develop neurobiologically plausible models for "stellate", "bushy", and "fusiform" cells of the CN based on the hypothesis that the membrane of different cell types has either voltage-independent conductance or distinct voltage-dependent nonlinear conductance; the models will attempt to reproduce cell-specific current-voltage and spike discharge characteristics in response to intracellular currents or to synaptic inputs; and (6) to develop neurobiologically plausible models for several classes of CN neurons exhibiting band-pass modulation transfer functions (MTFs), e.g., "pause- build" and sustained "chopper" neurons, and other CN neurons exhibiting low-pass MTFs, e.g., transient "chopper" neurons; the model predictions will bc closely compared with actual neural responses. The experimental methods will include obtaining population responses of auditory nerve fibers and cochlear nucleus neurons in unanesthetized decerebrate cats by sequentially recording from a large number of single neurons/fibers while applying an identical set of acoustic stimuli. The neural modeling studies will use digital computer simulation of neurons represented by an equivalent circuit for the cell membrane and a spike generation mechanism. The scientific information and theories to be obtained from this proposed research should be valuable in the long run to advance our understanding of the normal function of the auditory system and how the hearing capacities of disordered human auditory systems are degraded and, ultimately, in developing effective prostheses that can improve the hearing capacity of people with sensorineural hearing loss.

这项研究的长期目标是提高我们的理解 声学编码和处理的神经机制 听觉途径的尾部部分中的信号，即听觉 神经（AN）和耳蜗核（CN）。 我们的具体目的是：（1） 研究纯行为强度歧视的神经基础 通过检查空间来安静和掩盖噪音的音调 以d（e）方式定义的可区分性度量的概况 各种自发率（SR）的心理物理信号检测理论 纤维的种群； （2）研究一个神经基础 纯音的行为频率歧视的种群 以某种方式检查可区分性度量D（e）的空间概况 类似于上述强度歧视研究； （3）进行 人口研究纤维的反应和几类CN 神经元到复杂信号（元音和辅音元音音节） 以安静和掩盖的噪音呈现，并描绘 光谱传播复杂信号表示的转换 发生在AN和几类CN神经元中的每一个之间； （4）研究CN神经元编码振幅调节的行为 安静和掩盖噪音的音调，并将它们与 纤维； “斩波器”子类神经元的不同行为和 “暂停”神经元将被阐明，并将其比较 CN神经元模型的预测； （5）在神经生物学上发展 CN的“星状”，“浓密”和“梭形”细胞的合理模型 基于以下假设：不同细胞类型的膜具有 不依赖电压的电导或明显的电压依赖性 非线性电导；这些模型将尝试重现细胞特异性 电流 - 电压和尖峰放电特性 细胞内电流或突触输入； （6）发展 几类CN神经元的神经生物学上合理的模型 表现出频道调制传递函数（MTF），例如，暂停 - 构建和持续的“斩波器”神经元以及其他CN神经元展示 低通MTF，例如瞬态“切碎器”神经元；模型预测 BC将与实际的神经反应密切相比。 实验 方法将包括获得听觉神经的人群反应 一纤维和耳蜗核神经元在未经麻醉的杂交猫中通过 从大量的单个神经元/纤维中依次记录 应用一组相同的声学刺激。 神经建模 研究将使用由以 细胞膜和尖峰产生的等效电路 机制。 从中获得的科学信息和理论 从长远来看，这项拟议的研究应该很有价值，以促进我们的 了解听觉系统的正常功能以及如何 人类听觉系统无序的听力能力被降解，并且， 最终，在开发有效的假肢时可以改善 感官听力损失的人的听力能力。