Ultrastructural examination of the somatic innervation of ventrotubercular cells in the rat.
Ultrastructural examination of the somatic innervation of ventrotubercular cells in the rat.
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大鼠腹结核细胞体神经支配的超微结构检查。
DOI：
10.1002/cne.10603
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Ryugo,DavidK
中科院分区：
文献类型：
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作者：
Friedland,DavidR;Pongstaporn,Tan;Doucet,JohnR;Ryugo,DavidK
血管结节细胞是位于耳蜗腹核(VCN)内的多极细胞，向同侧耳蜗背核(DCN)投射侧支轴突。这些细胞被认为参与了使DCN输出神经元对代表空间声源位置的频谱形状敏感的过程。本报告着重于这一通路的神经元组成。猫和小鼠的细胞内标记研究描述了两种类型的腹结节细胞(Smith和Rhode[1989]J Comp Neurol)。282：595-626；Oertel等人[1990]J Comp Neurol.295：136-154)。在猫中，这两类细胞的一个不同之处在于，I型多极神经元不到35%的体细胞与终末相对，而II型细胞有超过70%的对位值。然而，从单个细胞进行细胞内记录是困难的，因此限制了数据的产量。我们调查了腹结节通路的两组分描述是否能代表更大的人群。这个问题是通过将生物素化的葡聚糖胺细胞外注射到大鼠的DCN逆行标记腹结节神经元来解决的。这些注射标记了许多VCN神经元，因此比以前的研究提供了更完整的通路视图。选择38个标记细胞进行电子显微镜分析，观察它们的位置、胞体大小和超微结构。我们观察到了标记的I型和II型神经元，但与猫的腹结节细胞不同，大鼠的许多这些神经元(38个细胞中的17个)的对应度在35%到70%之间。在这一分析的基础上，发现了第三类腹结节细胞，称为树突状神经元。树突状神经元胞体小，有许多丝状附属物，未见树突，终末对位百分率高(80%)。结果表明，大鼠的腹结节通路是多样的。J.Comp.神经。459：77-89,2003。©2003 Wiley-Liss，Inc.
Ventrotubercular cells are multipolar cells in the ventral cochlear nucleus (VCN) that project a collateral axon to the ipsilateral dorsal cochlear nucleus (DCN). These cells are thought to be involved in sensitizing DCN output neurons to spectral shapes that represent the location of a sound source in space. The present report focused on the neuronal composition of this pathway. Intracellular labeling studies in cats and mice have described two types of ventrotubercular cells (Smith and Rhode [1989] J Comp Neurol. 282: 595–626; Oertel et al.[1990] J Comp Neurol. 295: 136–154). In cats, one difference between the two classes is that type I multipolar neurons have fewer than 35% of their somata apposed by terminals, whereas type II cells have greater than 70% apposition values. Intracellular recordings from single cells, however, are difficult and thus limit the yield of data. We investigated whether a two-component description of the ventrotubercular pathway was representative of a larger population. This issue was addressed by retrogradely labeling ventrotubercular neurons with an extracellular injection of biotinylated dextran amine into the DCN of rats. These injections labeled many VCN neurons, thus providing a more complete view of the pathway than previous studies. Thirty-eight labeled cells were selected for electron microscopic analysis with respect to their location, cell body size, and ultrastructural morphology. We observed labeled type I and type II neurons, but unlike ventrotubercular cells in cats, many of these neurons in rats (17 of 38 cells) had appositions between 35% and 70%. On the basis of this analysis, a third class of ventrotubercular cell, called the adendritic neuron, was revealed. Adendritic neurons have small somata with many filopodial appendages, no observable dendrites, and high percentage of terminal appositions (80%). The results demonstrated that the ventrotubercular pathway in the rat is diverse. J. Comp. Neurol. 459: 77–89, 2003.© 2003 Wiley-Liss, Inc.