Neuroanatomy of the Auditory System

听觉系统的神经解剖学

• 批准号: 6783092
• 负责人: Nell B. Cant
• 金额: $ 5万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6783092
• 关键词: auditory cortex; auditory nuclei; auditory pathways; axon; brain mapping; cell type; gerbil /jird; histochemistry /cytochemistry; immunocytochemistry; inferior colliculus; innervation; neuroanatomy; neuronal transport; olivary body

The long-term objective is to understand the organization of the brainstem auditory pathways in terms of connections among the multiple neuronal types that form them. The objective of the proposed studies is an analysis of the termination patterns of specific cell types projecting into and out of the inferior colliculus (IC) of the gerbil. Nine experiments are proposed to achieve three specific aims: 1) To further characterize a) the multipolar cell pathway(s) from the ventral cochlear nucleus to the IC and b) the fusiform and giant cell pathways from the dorsal cochlear nucleus to the IC; 2) To determine the extent to which the descending projections from the auditory cortex to the IC overlap with ascending projections from the superior olivary complex versus those from the cochlear nuclei; 3) To determine whether different collicular domains give rise to projections to different parts of the medial geniculate nucleus. The working hypothesis that unites the specific aims is that zones in the inferior colliculus can be identified which are the targets of specific subsets of the ascending pathways and, further, that these zones project differentially into the forebrain. Neuroanatomical methods to be employed include techniques based on the anterograde and/or retrograde axonal transport of various tracer molecules; immunocytochemistry, and histochemistry. Neuroanatomical studies such as the ones proposed provide information essential for reaching an understanding of the mechanisms of auditory processing. The neuronal activity that leads to functional expression is dependent on the precise and specific connections among the hundreds of specialized neuronal types which collectively form the auditory system. Detailed understanding of these connections will not only help to explain available functional data, they will also provide a basis for developing rational hypotheses about auditory function that can be tested further.

长期目标是根据形成脑干听觉通路的多种神经元类型之间的连接来了解脑干听觉通路的组织。拟议研究的目的是分析伸入和伸出沙鼠下丘（IC）的特定细胞类型的终止模式。 提出九个实验来实现三个具体目标：1）进一步表征a）从腹侧耳蜗核到IC的多极细胞通路和b）从背侧耳蜗核到IC的梭形和巨细胞通路； 2) 确定从听觉皮层到 IC 的下降投影与来自上橄榄复合体的上升投影与来自耳蜗核的上升投影的重叠程度； 3) 确定不同的丘域是否会产生对内侧膝状核不同部分的投射。 统一特定目标的工作假设是，可以识别下丘中的区域，这些区域是上升路径的特定子集的目标，并且进一步，这些区域以不同的方式投射到前脑中。 所采用的神经解剖学方法包括基于各种示踪分子的顺行和/或逆行轴突运输的技术；免疫细胞化学和组织化学。神经解剖学研究（例如所提出的研究）提供了理解听觉处理机制所必需的信息。 导致功能表达的神经元活动取决于共同形成听觉系统的数百种专门神经元类型之间的精确和特定连接。 对这些连接的详细理解不仅有助于解释可用的功能数据，还将为开发有关听觉功能的合理假设提供基础，并可以进一步测试这些假设。