SYNAPTIC ORGANIZATION OF THE AUDITORY SYSTEM

我们将研究处理单耳和双耳的突触基础。 下丘(IC)的双耳信息。为了 定义IC中神经处理的解剖基础， 我们将结合轴突运输，细胞内染色， 定量方法和免疫细胞化学在光(LM)和 电子显微镜(EM)水平。每个实验都将解决 IC中的神经反应是一种产物的一般假设 由带状输入和特定单元定义的功能区 类型。 要确定IC的输入是否收敛以创建 特定的功能区，两个带状输入将在 同样的实验。我们假设来自不同来源的波段 重叠形成功能截然不同的突触结构域 颈内动脉内的神经纤维区。 表征双耳输入的突触组织 在高级橄榄复合体(SOC)中，我们将使用EM 并测试从SOC输入的假设 可以通过它们的精细结构来识别。我们预测了这些投入 将提供最多数量的兴奋性突触(类型1) 中央核团。 识别到突触区域的抑制性输入并 确定这些突触的来源，实验将结合 轴突运输方法确定输入和 EM水平的免疫细胞化学检测GABA或甘氨酸。 定量分析将检验这一假设，即突触 精细的结构取决于神经递质。如果有多个 找到含有GABA或甘氨酸结尾的来源， 可以研究IC的每个抑制输入的结构。 最后，为了定义通过IC的功能路径， 将使用逆行标记和细胞内染色的方法 以识别IC中的特定细胞类型；同时， 顺行标记将用于标识特定的上升方向 输入到这些单元格。我们假设突触的内容 与特定像元类型相关的属性域将创建不同的 处理听觉不同方面的输出通路 信息。

We will investigate the synaptic bases for processing monaural and binaural information in the inferior colliculus (IC). In order to define the anatomical substrates of neural processing in the IC, we will combine axonal transport, intracellular staining, quantitative methods, and immunocytochemistry at the light (LM) and electron microscopic (EM) levels. Each experiment will address the general hypothesis that neural responses in the IC are a product of functional zones defined by banded inputs and specific cell types. To determine whether the inputs to the IC converge to create specific functional zones, two banded inputs will be labeled in the same experiment. We postulate that bands from different sources overlap to form synaptic domains which are functionally distinct zones of neuropil in the IC. To characterize the synaptic organization of the binaural inputs from the superior olivary complex (SOC), we will use EM autoradiography and test the hypothesis that inputs from the SOC can be identified by their fine structure. We predict these inputs will provide the largest number of excitatory synapses (type 1) to the central nucleus. To identify the inhibitory inputs to the synaptic domains and determine the sources of these synapses, experiments will combine axonal transport methods to determine the inputs and immunocytochemistry at the EM level to detect GABA or glycine. Quantitative analyses will test the hypothesis that the synaptic fine structure depends on the neurotransmitter. If multiple sources of GABA or glycine-containing ending are found, the structure of each inhibitory input to the IC can be investigated. Finally, to define the functional pathways through the IC, retrograde labeling an intracellular staining methods will be used to identify specific cell types in the IC; simultaneously, an anterograde marker will be used to identify a specific ascending input to these cells. We postulate that the content of synaptic domains in relation to specific cell types will create distinct output pathways to process different aspects of auditory information.