UNMYELINATED AXONS OF THE AUDITORY-NERVE IN CATS
UNMYELINATED AXONS OF THE AUDITORY-NERVE IN CATS
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DOI：
10.1002/cne.903080208
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发表时间：
1991-06-08
影响因子：
2.5
通讯作者：
KIANG, NYS
中科院分区：
文献类型：
--
作者：
RYUGO, DK;DODDS, LW;KIANG, NYS
用辣根过氧化物酶（HRP）标记猫听神经Ⅱ型螺旋神经节神经元的中枢终末。 用二氨基联苯胺进行组织学处理后，对听神经的粗纤维（2-4 μ m）和细纤维（0.5 μ m）进行染色。 无论何时追踪，粗纤维总是来自I型螺旋神经节神经元，细纤维总是来自II型神经节神经元。 由于II型轴突的标记褪色的纤维投射到耳蜗核，本报告仅限于区域的腹侧耳蜗核附近的听神经根。 II型神经元的中央轴突是无髓鞘的，在耳蜗核中具有简单但可变的分支模式，并形成途中和末端肿胀。 在光学显微镜下，大部分的神经鞘位于神经鞘中，但它们也被发现在细胞体，I型轴突的朗维尔结和血管附近。 18个在neurostheses通过光学显微镜和切除的电子显微镜，这些sostheses表现出化学突触的超微结构特征。 数据表明，来自外毛细胞的输入可能能够通过II型初级神经元影响耳蜗核的听觉处理。
This paper describes some central terminations of type II spiral ganglion neurons as labeled by extracellular injections of horseradish peroxidase (HRP) into the auditory nerve of cats. After histological processing with diaminobenzidine, both thick (2-4-mu-m) and thin (0.5-mu-m) fibers of the auditory nerve were stained. Whenever traced, thick fibers always originated from type I spiral ganglion neurons and thin fibers always from type II ganglion neurons. Because the labeling of type II axons faded as fibers projected into the cochlear nucleus, this report is limited to regions of the ventral cochlear nucleus near the auditory nerve root. The central axons of type II neurons are unmyelinated, have simple yet variable branching patterns in the cochlear nucleus, and form both en passant and terminal swellings. Under the light microscope, most swellings are located in the neuropil but they are also found in the vicinity of cell bodies, nodes of Ranvier of type I axons, and blood vessels. Eighteen en passant swellings in the neuropil were located by light microscopy and resectioned for electron microscopy; two of these swellings exhibited ultrastructural features characteristic of chemical synapses. The data indicate that inputs from outer hair cells might be able to influence auditory processing in the cochlear nucleus through type II primary neurons.