DEVELOPMENT/INFLUENCE--INHIBITION IN AUDITORY SYSTEM

总体目标是全面描述 中枢神经抑制的功能和结构发展 沙鼠的听觉核团(长爪沙鼠)。这项研究 计划可分为三个具体领域：(1)功能 发展。抑制性和兴奋性的发育性表现 将量化外侧上橄榄核的突触后电位 (LSO)神经元，用沙土鼠脑片制备。延迟时间， 突触后电位的幅度和数量将用 来自动物的标准细胞内技术增加出生后 年龄。(2)解剖发育。植物轴突乔木的成熟过程 投射抑制核，梯形小体的内侧核 (MNTB)，将通过细胞内填充染料获得LSO 流程。它们的绝对大小以及它们的解剖分布 将对乔木进行评估。特别感兴趣的是两个描述性的 实验，将是任何迹象缺乏特异性在 功能抑制接触，旺盛的轴突乔木)。(3) 神经抑制对个体发育的影响。发展中的 从功能上消除抑制投射到 LSO将通过两种方式进行评估。抑制活性对细胞生长的影响 将通过测量LSO细胞大小来分析突触后结构。这个 将通过测量刺激来评估对听觉功能的影响 LSO神经元的特异性和兴奋性的相对效应 和抑制性传入通路。这些实验将有助于 我们对这些听觉编码特性成熟的理解 依赖于抑制，以及中央的退行性变化 伴随传导性和感觉神经性听力损失的听觉系统。

The overall goal is to provide a comprehensive description of the functional and structural development of neural inhibition in a central auditory nucleus of the gerbil (Meriones unguiculatus). The research plan can be divided into three specific areas: (1) Functional development. The developmental appearance of inhibitory and excitatory postsynaptic potentials will be quantified in lateral superior olivary (LSO) neurons, using the gerbil brain slice preparation. The latency, amplitude, and number of postsynaptic potential will be measured with standard intracellular techniques from animals of increasing postnatal age. (2) Anatomical development. The maturation of axonal arbors from a projection inhibitory nucleus, the medical nucleus of the trapezoid body (MNTB), to the LSO will be obtained by intracellular dye-filling of the processes. The absolute size, and the anatomical distribution of each arbor will be evaluated. Of particular interest in the two descriptive experiments, will be any indications of a lack of specificity during functional inhibitory contacts, exuberant axonal arbors). (3) Ontogenetic influence of neural inhibition. The developmental consequences of functionally eliminating the inhibitory projection to the LSO will be assessed in two ways. The effects of inhibitory activity on postsynaptic structure will be assayed by measuring LSO cell size. The effects on auditory function will be assayed by measuring the stimulus specificity of LSO neurons and the relative efficacy of the excitatory and inhibitory afferent pathways. These experiments will contribute to our understanding of the maturation of those auditory coding properties which rely on inhibition, and the degenerative changes in the central auditory system attendant to conductive and sensorineural hearing loss.