Axonal pathways to the lateral superior olive labeled with biotinylated dextran amine injections in the dorsal cochlear nucleus of rats
Axonal pathways to the lateral superior olive labeled with biotinylated dextran amine injections in the dorsal cochlear nucleus of rats
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DOI：
10.1002/cne.10722
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发表时间：
2003-07-07
影响因子：
2.5
通讯作者：
Ryugo, DK
中科院分区：
文献类型：
--
作者：
Doucet, JR;Ryugo, DK
侧上橄榄（LSO）包含对两只耳朵之间的强度差异敏感的细胞，这是大脑在空间中定位声音的一种特征。本报告描述了一个输入到LSO的来源，它补充了来自耳蜗腹侧核（VCN）的丛状细胞投影。将生物素化右旋糖酐胺（BDA）注射到大鼠耳蜗背核（DCN）的标记轴突和几个脑干结构的肿胀，包括同侧LSO。同侧LSO的标记被限制在一个薄带，延伸到整个结构的长度，使其类似于LSO的同频层。这种标记通路的来源并不明显，因为DCN神经元没有投射到LSO， VCN丛状细胞也没有被这些注射填充。几个脑干结构中充满的神经元可能是来源。三个观察结果表明，大多数轴突标记在LSO来自一个单一的来源。首先，标记的VCN平面多极细胞数量和LSO中标记的数量在动物之间是一致的和稳健的。相比之下，大多数其他结构中标记的细胞数量很少，而且变化很大。其次，LSO中平面细胞和填充轴突的位置与DCN注射部位的位置在地形上相关。第三，LSO中有标记的末端分枝来自于梯形体（平面细胞的输出束）轴突的侧枝。我们推断，平面多极细胞，除了浓密细胞，是从耳蜗核上升输入到LSO的来源。(C) 2003 Wiley-Liss, Inc。
The lateral superior olive (LSO) contains cells that are sensitive to intensity differences between the two ears, a feature used by the brain to localize sounds in space. This report describes a source of input to the LSO that complements bushy cell projections from the ventral cochlear nucleus (VCN). Injections of biotinylated dextran amine (BDA) into the dorsal cochlear nucleus (DCN) of the rat label axons and swellings in several brainstem structures, including the ipsilateral LSO. Labeling in the ipsilateral LSO was confined to a thin band that extended throughout the length of the structure such that it resembled an LSO isofrequency lamina. The source of this labeled pathway was not obvious, because DCN neurons do not project to the LSO, and VCN bushy cells were not filled by these injections. Filled neurons in several brainstem structures emerged as possible sources. Three observations suggest that most of the axonal labeling in the LSO derives from a single source. First, the number of labeled VCN planar multipolar cells and the amount of labeling in the LSO were consistent and robust across animals. In contrast, the number of labeled cells in most other structures was small and highly variable. Second, the locations of planar cells and filled axons in the LSO were related topographically to the position of the DCN injection site. Third, labeled terminal arborizations in the LSO arose from collaterals of axons in the trapezoid body (output tract of planar cells). We infer that planar multipolar cells, in addition to bushy cells, are a source of ascending input from the cochlear nucleus to the LSO. (C) 2003 Wiley-Liss, Inc.