MORPHOLOGY & CONNECTIONS OF THE SPIRAL GANGLION

听觉信息编码与加工的理论研究进展 作为他们的出发点，有大量的详细信息， 猫的单个听觉神经纤维的反应特性，但我们的 理解初级传入输入的潜在组织 耳蜗核（CN）的神经传导非常有限。总体目标 建议的研究是提供有关的基本信息， 耳蜗螺旋神经节的形态结构和联系 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)精确绘制脊神经节投射的地形图 耳蜗腹侧核的亚群和细胞类型 显微注射到脊神经节;在这些实验中， 进一步定义频率代表维度和 神经节内垂直位置详细投影到打击 CN的主要分支的“Islaminae”。2)以确定 螺旋神经节细胞如何服从不同的已知类别的IHC 传入终末分布在垂直方向的投射中 以及罗森塔尔氏管的纵向尺寸3)来定义 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 频率，潜伏期，Q-10 dB）的“缺血层”内和之间 腹侧耳蜗核分裂，并将这些发现与 HRP实验中证明的CN投影图案的形态。4)到 确定CN投影图案是保持静态还是经历 耳毒性药物诱导后的地形重组 感音神经性耳聋和随之而来的严重变性和改变， 螺旋神经节神经元 这些拟议的实验将更详细地定义 组织耳蜗投射到CN，从而增加 我们对信息处理的解剖结构的理解 周围听觉系统的机械装置。这些数据对于 建立更完整的听觉中枢处理模型 这些信息应该是许多调查人员非常感兴趣的。 拟议的病理性耳蜗研究具有临床意义， 他们进一步定义了：1）诱发耳蜗退化的因素 神经; 2）神经节细胞的CN投射的性质 在严重耳聋病理学中幸存下来。这些独特研究的数据 记录CN输入变更的时间过程和程度 耳聋发作对疗效有实际影响， 在具有类似病理的患者中优化人工耳蜗植入物。

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.