MORPHOLOGY & CONNECTIONS OF THE SPIRAL GANGLION

关于听觉信息编码和处理的现有理论 有大量关于以下方面的详细信息作为起点 猫单个听神经纤维的反应特性，但我们的 了解基本传入输入的基本组织结构 对耳蜗核(CN)的影响非常有限。总体目标 建议进行的研究的目的是提供有关 耳蜗螺旋神经节的形态组织和联系 成年猫的神经元。生理记录和细胞化学标记 结合广泛的光学和电子显微镜分析的技术 将在这些研究中使用。我们的目标包括： 1)绘制脊神经节投影的详细地形图 利用HRP对耳蜗核腹侧核的细分和细胞类型的研究 脊神经节内微量注射；在这些实验中， 进一步定义频率表征维度和 节内垂直位置法详细介绍打击 核团各主要亚部的“等频板”。2)确定 螺旋神经节细胞如何为不同类型的IHC提供服务 传入终末分布在垂直方向上的投影中 以及罗森塔尔运河的纵向尺寸。3)定义 某些生理反应特性的地形分布 (其中，特征频率、阈值、自发放电 速率、潜伏期、Q-10分贝)内和之间 腹侧耳蜗核的分裂，并将这些发现与 HRP实验证明了CN投射图案的形态。4)至 确定CN投射模式是保持静止还是经历 耳毒性药物诱导后的脑电地形图重建 感音神经性耳聋及其导致的严重变性和改变 螺旋神经节神经元。 这些拟议的实验将更详细地定义 组织到CN的耳蜗投射，从而增加 我们对信息处理的解剖框架的理解 外周听觉系统的机械。这些数据对以下方面很重要 建立更完整的听觉中枢加工模型 这些信息应该是许多调查人员非常感兴趣的。 拟议中的病理耳蜗学研究具有临床意义，如 他们进一步定义：1)导致耳蜗变性的因子(S) 2)神经节细胞发出的CN投射的性质 从严重耳聋的病理中幸存下来。来自这些独特研究的数据 记录后CN投入的时间进程和变更程度 耳聋的发病具有实际意义，涉及的有效性和 病理相似患者人工耳蜗术式的优化。

Current theories regarding encoding and processing of auditory information have as their starting point a large body of detailed information on response properties of single auditory nerve fibers in cats, yet our understanding of the underlying organization of the primary afferent inputs to the cochlear nucleus (CN) is remarkably limited. The overall objective of the proposed studies is to provide fundamental information about the morphological organization and connections of cochlear spiral ganglion neurons in adult cats. Physiological recording and cytochemical labeling techniques combined with extensive light and electron microscopic analyses will be employed in these studies. Among our objectives are the following: 1) To map in fine detail the topography of the spinal ganglion projection to ventral cochlear nucleus subdivisions and cell types, utilizing HRP microinjections into the spinal ganglion; and in these experiments, to further define how the frequency representational dimension and intraganglionic vertical position project in detail onto the striking "isofrequency laminae" of the major subdivisions of the CN. 2) To determine how spiral ganglion cells subserving different known classes of IHC afferent terminals are distributed in their projections across the vertical and longitudinal dimensions of Rosenthal's canal. 3) To define the topographic distributions of certain physiological response properties (among them, characteristic frequency, threshold, spontaneous discharge rate, latency, Q-10dB) within and between the "isofrequency laminae" of ventral cochlear nucleus divisions, and to relate those findings to the morphology of CN projection patterns demonstrated in HRP experiments. 4) To determine whether CN projection patterns remain static or undergo topographic reorganization after ototoxic drug induction of profound sensorineural deafness and consequent severe degeneration and alteration of spiral ganglion neurons. These proposed experiments will define in much richer detail the organization of the cochlear projections to the CN, and thereby increase our understanding of the anatomical framework of the information processing machinery of the peripheral auditory system. Such data are important for formulating more complete models of the central processing of auditory information and should be of critical interest to many investigators. Proposed studies in pathological cochleas are of clinical significance, as they further define: 1) factor(s) that induce degeneration of the cochlear nerve; and 2) the nature of the CN projections from ganglion cells surviving severe deafness pathology. Data from these unique studies documenting the time course and extent of alteration in CN inputs after deafness onset have practical implications regarding the efficacies and optimization of cochlear implants in patients with similar pathologies.