BUSHY CELLS IN THE ANTEROVENTRAL COCHLEAR NUCLEUS OF THE CAT - STUDY WITH THE ELECTRON-MICROSCOPE
BUSHY CELLS IN THE ANTEROVENTRAL COCHLEAR NUCLEUS OF THE CAT - STUDY WITH THE ELECTRON-MICROSCOPE
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DOI：
10.1016/0306-4522(79)90066-6
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发表时间：
1979-01-01
期刊：
影响因子：
3.3
通讯作者：
MOREST, DK
中科院分区：
文献类型：
--
作者：
CANT, NB;MOREST, DK
在前分裂的前部，由于其他类型的细胞很少，因此很容易识别出浓密细胞及其突起的轮廓。在前分裂的后部和后嗅觉部分，浓密的细胞与星状细胞和小细胞混杂在一起，但可以通过光镜描述和与前部结果的比较来识别。浓密细胞是大的球形细胞，细胞核位于中心，被粗糙的内质网片包裹。薄的近端树突突出细胞体，含有相对苍白的细胞质。远端树突除了大量的、非常大的线粒体外，几乎没有细胞器。细胞体细胞、近端树突和轴突丘有许多突触终结点，但远端树突突起的突触终结点相对较少。至少有4种终末与丛状细胞形成突触接触。非常大的末端，包含大的球形突触囊泡，形成多个不对称的接触，与耳蜗的耳蜗末球相对应。这些终末在人工耳蜗消融后消失，但其他3种终末仍然存在。其中数量最多的是一个大的末端，它包含扁平的突触囊泡，并与浓密细胞的体细胞和树突形成长而几乎对称的接触。第二类非耳蜗末梢较小，含有小的多形性突触囊泡，不扁平。第三种主要发生在浓密的细胞树突上，含有小的球形突触囊泡，并形成中度不对称的接触。浓密的细胞可能与电生理学研究中描述的前分裂的原代样细胞相对应。原代样单位以一对一的方式对听神经纤维的活动作出反应，这一发现与观察结果相一致，即大部分体细胞表面和丛状细胞的树突与听神经末梢（赫尔德的末梢球）接触。对毛囊细胞的几种非耳蜗输入的来源和功能都还不清楚。进一步分析这些输入和前分裂的其他神经元类型，并将其与来自相同细胞类型的生理生化数据相关联，可以阐明观察到的突触组织模式的功能意义。
In the anterior part of the anterior division, profiles of bushy cells and their processes are easily identified, since few cells of other types are found in this region. In the posterior and posterodorsal parts of the anterior division, the bushy cells are intermingled with stellate and small cells but can be identified on the basis of light-microscopic descriptions and comparisons with the results from the anterior part. Bushy cells are large, spherical cells with a centrally located nucleus enveloped by sheets of rough endoplasmic reticulum. Thin proximal dendrites jut abruptly from the cell body and contain a relatively pale cytoplasm. The distal dendrites contain few organelles other than numerous, very large mitochondria. The cell soma, proximal dendrites and the axon hillock receive numerous synaptic terminals, but the distal dendritic processes are contacted by relatively few endings. At least 4 types of terminals form synaptic contacts with the bushy cells. Very large terminals, containing large, spherical synaptic vesicles and forming multiple asymmetrical contacts, correspond to the end-bulbs of Held from the cochlea. These terminals disappear after cochlear ablations, but the other 3 types remain. The most numerous of these is a large terminal that contains flattened synaptic vesicles and forms long, nearly symmetrical contacts with the soma and dendrites of bushy cells. The 2nd type of non-cochlear terminal is smaller and contains small, pleiomorphic synaptic vesicles that are not flattened. The 3rd type occurs mainly on bushy cell dendrites, contains small, spherical synaptic vesicles and forms moderately asymmetrical contacts. The bushy cells probably correspond to the primarylike units described in electrophysiological studies of the anterior division. Primarylike units respond to activity in auditory nerve fibers in a one-to-one manner, a finding compatible with the observation that much of the surface of the soma and dendrites of the bushy cells is contacted by auditory nerve terminals (end-bulbs of Held). Neither the origins nor the functions of the several types of non-cochlear inputs to the bushy cells are known. Further analysis of these inputs and of the other neuronal types in the anterior division, when correlated with physiological and biochemical data from the same cell types, could clarify the functional significance of the observed patterns of synaptic organization.