An ultrastructural analysis of myelin in the central nervous system of an amphibian
10.1007/BF00224210 Cite this article as: Kemali, M. Cell Tissue Res. (1974) 152: 51. doi:10.1007/BF00224210 Summary
An ultrastructural analysis of myelin in the ventral habenular and in the interpeduncular nuclei of the adult frog
Rana esculenta has been carried out. In the ventral habenular nuclei, in addition to normally myelinated fibres, some myelin irregularities have been observed. They consist of myelin enwrapping the perikarya of some neurons and of isolated flaps of collapsed myelin. In the interpeduncular nucleus numerous myelinated fibres occur but few redundant myelin irregularities have been noticed.
The morphological data suggest that myelination of fibres in these sites is due to the spiral wrapping mechanism from a glial cell process while the myelin irregularities described in the ventral habenular nuclei are probably due to membrane synthesis within the cytoplasm of the myelinated neurons and of the oligodendrocytes which are sometimes observed in contact with the ensheathed neurons. In the interpeduncular nucleus myelinated fibres indenting astrocytes and oligodendrocytes have been observed.
Key words Myelin Ventral habenular nuclei Interpeduncular nucleus Rana esculenta Electron microscopy
The autor would like to express appreciation to Dr. R. Martin of Stazione Zoologica, Naples, for his constant support and to Mr. G. Dafnis for his assistance at the electron microscope.
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