SOME OBSERVATIONS ON THE FINE STRUCTURE OF THE GIANT NERVE FIBERS OF THE EARTHWORM, EISENIA-FOETIDA
SOME OBSERVATIONS ON THE FINE STRUCTURE OF THE GIANT NERVE FIBERS OF THE EARTHWORM, EISENIA-FOETIDA
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DOI：
10.1083/jcb.6.1.61
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发表时间：
1959-01-01
期刊：
影响因子：
--
通讯作者：
HAMA, K
中科院分区：
文献类型：
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作者：
HAMA, K
用电镜观察了赤子海葵背侧巨纤维的形态结构。巨大的轴突被雪旺氏鞘包围，鞘中的薄片呈平行排列。它们可以从许旺细胞的外表面追踪到轴突-许旺膜。螺旋排列中的不规则现象经常被观察到。桥粒样附着区出现在巨大的纤维神经鞘上。这些结构似乎被安排在列，这是定向略倾斜的巨纤维的长轴和线性排列从轴突到鞘的外周两侧。在这些部位，它们结合在一起，构成鞘的许旺细胞膜的相对部分。神经鞘附着区的纵切面或斜切面使人联想到脊椎动物周围神经的施密特-兰特曼裂隙。巨大纤维的隔膜已被检查。它们是对称的或非极化的，由相邻神经单位的两个质膜组成。特征性囊泡和管状结构与这些隔膜的细胞质表面相关。
Sectioned dorsal giant fibers of the earthworm Eisenia foetida have been studied with the electron microscope. The giant axon is surrounded by a Schwannian sheath in which the lamellae are arranged spirally. They can be traced from the outer surface of the Schwann cell to the axon-Schwann membranes. Irregularities in the spiral arrangement are frequently observed. Desmosome-like attachment areas occur on the giant fiber nerve sheath. These structures appear to be arranged bilaterally in columns which are oriented slightly obliquely to the long axis of the giant fiber and aligned linearly from the axon to the periphery of the sheath. At these sites they bind together apposing portions of Schwann cell membrane comprising the sheath. Longitudinal or oblique sections of the nerve sheath attachment areas are reminiscent of the Schmidt- Lantermann clefts of vertebrate peripheral nerve. Septa of the giant fibers have been examined. They are symmetrical or nonpolarized and consist of the two plasma membranes of adjacent nerve units. Characteristic vesicular and tubular structures are associated with both cytoplasmic surfaces of these septa.