Commissural Neurons in the Rat Ventral Cochlear Nucleus
Commissural Neurons in the Rat Ventral Cochlear Nucleus
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DOI：
10.1007/s10162-008-0155-6
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发表时间：
2009-06-01
影响因子：
2.4
通讯作者：
May, Bradford J.
中科院分区：
文献类型：
--
作者：
Doucet, John R.;Lenihan, Nicole M.;May, Bradford J.
连合神经元连接双耳的耳蜗核复合体。先前的研究表明，神经元可以根据并置百分比（PA）分为两种解剖亚型；也就是说，突触末端所占的体细胞百分比。本研究将束追踪与突触免疫标记相结合，比较大鼠耳蜗腹核（VCN）中 I 型（低 PA）和 II 型（高 PA）连合神经元的体细胞面积、相对数量和位置。共聚焦显微镜分析显示，377 个连合神经元中的 261 个 (69%) 具有中等大小的体细胞，具有 I 型轴体神经支配。连合神经元也表现出不同的拓扑分布。大多数 I 型神经元位于 VCN 的小细胞帽中，它是听觉脑干内调节通路的纽带。大多数 II 型神经元存在于大细胞核心中。这种解剖学二分法应该拓宽目前对连合通路功能的看法，该通路强调 II 型神经元产生的快速抑制相互作用。更普遍的 I 型神经元可能会产生缓慢的调节影响，从而增强双耳处理或损伤后功能的恢复。
Commissural neurons connect the cochlear nucleus complexes of both ears. Previous studies have suggested that the neurons may be separated into two anatomical subtypes on the basis of percent apposition (PA); that is, the percentage of the soma apposed by synaptic terminals. The present study combined tract tracing with synaptic immunolabeling to compare the soma area, relative number, and location of Type I (low PA) and Type II (high PA) commissural neurons in the ventral cochlear nucleus (VCN) of rats. Confocal microscopic analysis revealed that 261 of 377 (69%) commissural neurons have medium-sized somata with Type I axosomatic innervation. The commissural neurons also showed distinct topographical distributions. The majority of Type I neurons were located in the small cell cap of the VCN, which serves as a nexus for regulatory pathways within the auditory brainstem. Most Type II neurons were found in the magnocellular core. This anatomical dichotomy should broaden current views on the function of the commissural pathway that stress the fast inhibitory interactions generated by Type II neurons. The more prevalent Type I neurons may underlie slow regulatory influences that enhance binaural processing or the recovery of function after injury.