Summary
Radioactive choline injected into mouse sciatic nerve is rapidly incorporated into phosphatidylcholine. Sites of deposition of this phospholipid have been localized along the internode in autoradiographs prepared from individually teased fibres.
The newly synthesized lecithin formed during 20 min or 2 h labelling periods is concentrated in the perinuclear region of the Schwann cell and in strands radiating from this portion of the cell. This labelling pattern, representing a complex of enzyme activities, is distributed in a similar, though not identical, fashion to that of Schwann cell mitochondria as localized by histochemical methods. These findings suggest that soluble and membrane-associated enzymes required for phosphatidylcholine formation are distributed in Schwann cell cytoplasm along superficial longitudinally oriented channels as depicted in recent freeze-fracture studies.
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References
Berthold, C.-H. &Skoglund, S. (1967) Histochemical and ultrastructural demonstration of mitochondria in the paranodal region of developing feline spinal roots and nerve.Acta societatis medicorum upsaliensis 72, 37–70.
Berthold, C.-H. (1968) A study on the fixation of large mature feline myelinated ventral lumbar spinal-root fibres.Acta societatis medicorum upsaliensis 73, Suppl. 9, 1–37.
Dawson, R. M. C. &Gould, R. M. (1976) Renewal of phospholipids in the myelin sheath. InFunction and Metabolism of Phospholipids in the Central and Peripheral Nervous System (edited byPorcellati, G.), pp. 95–113. New York: Plenum Press.
Dyck, P. J. &Lais, A. C. (1970) Electron microscopy of teased nerve fibers. A method permitting examination of repeating structure, of same fiber.Brain Research 23, 418–24.
Gould, R. M. &Dawson, R. M. C. (1976) Incorporation of newly formed lecithin into peripheral nerve myelin.Journal of Cell Biology 68, 480–96.
Gould, R. M. (1977) Incorporation of glycoproteins into peripheral nerve myelin.Journal of Cell Biology 75, 326–38.
Hayat, M. A. (1972)Basic Electron Microscopy Techniques. New York: Van Nostrand Reinhold.
Horrocks, L. A. (1967) Composition of myelin from peripheral and central nervous systems of the squirrel monkey.Journal of Lipid Research 8, 569–76.
Klein, F. &Mandel, P. (1976) Lipid composition of rat sciatic nerve.Lipids 11, 506–12.
Kopriwa, B. (1975) A comparison of various procedures for fine grain development in electron microscopic autoradiography.Histochemistry 44, 201–24.
Kruger, L., Stolinski, C., Martin, B. G. H. &Gross, M. G. (1979) Membrane specializations and cytoplasmic channels of Schwann cells in mammalian peripheral nerve seen in freeze-fracture replicas.Journal of Comparative Neurology 186, 578–602.
Kumara-Siri, M. H. &Gould, R. M. (1980) Enzymes of phospholipid synthesis: axonal versus Schwann cell distribution.Brain Research 186, 315–30.
Landon, D. N. &Hall, S. (1976) The myelinated nerve fibre. InThe Peripheral Nerve (edited byLandon, D. N.), pp. 1–105. London: Chapman and Hall.
McCaman, R. E. &Cook, K. (1966) Intermediary metabolism of phospholipids in brain tissue. III. Phosphocholine-glyceride transferase.Journal of Biological Chemistry 241, 3390–4.
Mugnaini, E., Osen, K. K., Schnapp, B. &Friedrich, V. L., Jr (1977) Distribution of Schwann cell cytoplasm and plasmalemmalvesicles (caveolae) in peripheral myelin sheaths. An electron microscopic study with thin sections and freeze-fracturing.Journal of Neurocytology 6, 647–68.
Peters, A. (1970) The fixation of central nervous tissue and the analysis of electron micrographs of the neuropil, with special reference to the cerebral cortex. InContemporary Research Methods in Neuroanatomy (edited byNauta, W. J. H. andEbbesson, S. O. E.), pp. 56–76. New York: Springer-Verlag.
Rawlins, F. A. (1973) A time-sequence autoradiographic study of thein vivo incorporation of [1,2-3H]cholesterol into peripheral nerve myelin.Journal of Cell Biology 58, 42–53.
Samorajski, T. &Friede, R. L. (1968) Size-dependent distribution of axoplasm, Schwann cell cytoplasm, and mitochondria in the peripheral nerve fibers of mouse.Anatomical Record 161, 281–92.
Spencer, P. S. &Thomas, P. K. (1970) The examination of isolated nerve fibres by light and electron microscopy, with observations on demyelination proximal to neuromas.Acta neuropathologica 16, 177–86.
Williams, P. L. &Landon, D. N. (1963) Paranodal apparatus of peripheral nerve fibres of mammals.Nature 198, 670–3.
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This paper is dedicated to the memory of the late Dr Frank A. Rawlins who, in such a short lifetime, contributed so much to our understanding of myelin lipid metabolism.
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Gould, R.M., Sinatra, R.S. Internodal distribution of phosphatidylcholine biosynthetic activity in teased peripheral nerve fibres: An autoradiographic study. J Neurocytol 10, 161–167 (1981). https://doi.org/10.1007/BF01257964
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DOI: https://doi.org/10.1007/BF01257964