ANATOMY OF COCHLEAR NUCLEUS--CORRELATION WITH PHYSIOLOGY

耳蜗核的解剖结构--与生理学的相关性

• 批准号: 6104415
• 负责人: DONALD KENT MOREST
• 金额: $ 14.4万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 1999-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6104415
• 关键词: auditory feedback; auditory nuclei; auditory stimulus; autoradiography; axon; cats; cochlea; dendrites; electron microscopy; electrophysiology; gamma aminobutyrate; glycine; immunocytochemistry; laboratory rabbit; mathematical model; nerve endings; neural information processing; neuroanatomy; neurophysiology; psychoacoustics; radiotracer; soma; synapses; tritium

We shall explore the hypothesis that inhibitory processes within the cochlear nucleus modify the functional response of the brain to ongoing acoustic stimuli. Our approach is to determine the structural and neurochemical bases for the effects of local circuits on information processing in the cochlear nucleus and to link these findings to the physiological observations made on the same circuits in a companion project. The reciprocal, and possibly inhibitory, connections between specific types of neurons in the ventral and dorsal cochlear nucleus will be defined and their putative neurotransmitters localized. The plan is to identify the neuronal types involved in reciprocal connections between these nuclei by combining anterograde and retrograde tracing methods with the locations of the labeled neurons. The distribution of the synaptic endings on the labeled neurons will be mapped in their respective target areas in order to estimate their potential spheres of influence, to see if there is a discrete mapping of interconnections between neurons or if they project more diffusely to larger domains, corresponding to frequency bands of certain dimensions. Light and electron microscopic immunocytochemistry will be used in combination with anterograde and retrograde tracers to determine which of these projections supplies endings containing the inhibitory transmitters, glycine or GABA, to their target cells. The anatomical findings will be related to the physiological data by combining microscopic labeling of the reciprocal connections and physiological recording of the alterations in acoustical response properties induced by stimulating or inhibiting these connections. In the long term these studies will extend to other nuclei of the brain stem and their interconnections with the cochlear nucleus. This research will elucidate the roles of local circuits and inhibitory interneurons in monaural and binaural hearing. Ultimately they should provide insight into the neurobiology of perceptual phenomena, such as monaural echo suppression, binaural interactions, such as the precedence effect, and sensory control mechanisms in general.

我们将探讨的假设，抑制过程中， 耳蜗核修改大脑的功能反应， 声刺激 我们的方法是确定结构和 局部回路对信息作用的神经化学基础 处理耳蜗核，并将这些发现与 在同伴的相同回路上进行的生理学观察 项目 相互的，可能是抑制性的， 耳蜗腹侧核和背侧核中的特定类型的神经元将 并定位其假定的神经递质。 该计划是 以确定参与相互连接的神经元类型， 结合顺行和逆行追踪方法， 标记神经元的位置。 突触的分布 标记的神经元上的末端将被映射到它们各自的目标 地区，以估计其潜在的影响范围，以了解 如果神经元之间存在离散的互连映射，或者 它们更分散地投射到更大的域，对应于频率 某些维度的带。 光镜和电镜 免疫细胞化学将与顺行和 逆行示踪剂，以确定这些预测供应 末端含有抑制性递质，甘氨酸或GABA， 靶细胞 解剖学发现将与 生理数据通过结合显微标记的倒数 连接和生理记录的变化， 通过刺激或抑制这些细胞而诱导的反应特性 连接.从长远来看，这些研究将扩展到其他核 以及它们与耳蜗核的相互连接。 本研究将阐明局部回路和抑制性神经元的作用， 单耳和双耳听觉的中间神经元。 最终他们必须 提供洞察知觉现象的神经生物学，如 单声道回声抑制，双耳交互，如优先 影响和一般的感觉控制机制。