Visualization of oligodendrocytes and astrocytes in the intact rat optic nerve by intracellular injection of lucifer yellow and horseradish peroxidase
Tóm tắt
The morphology of glial cells in the intact rat optic nerve, a central nervous system (CNS) white matter tract, was analysed by filling over 500 macroglial cells intracellularly with horseradish peroxidase (HRP) or Lucifer yellow (LY). Two main cell types were distinguished: fibrous astrocytes and cells presumed to be oligodendrocytes. Intracellularly stained astrocytes were highly complex, with 50–60 long branching processes which passed radially from the cell body and terminated in end‐feet at the pial surface or on blood vessels; some processes ended freely in the nerve parenchyma. Astrocytes filled with LY were usually dye‐coupled to other astrocytes after the first week of life. Filled oligodendrocytes had a unique appearance that unmistakably distinguished them from astrocytes and were occasionally dye‐coupled to nearby oligodendrocytes. These cells had 20–30 longitudinally oriented processes 150–200 μm long, which passed exclusively along the long axis of the nerve parallel to axons; the longitudinal processes were connected to the cell body by thin branches 15–30 μm long. The longitudinal processes probably represent the tongue processes of the internodal myelin sheaths, and thus each oligodendrocyte appears to myelinate 20–30 axons with sheaths that are 150–200 μm in length.
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Tài liệu tham khảo
Del Rio‐Hortega P., 1928, Tercera aportacion al conocimiento morfologica e interpretación funcional de la oligodendroglia, Mem. Real Soc. Espan. Hist. Nat., 14, 5
Jones E. G., 1988, Cell and Tissue Biology, 278
Klatzo I., 1952, A study of glia by the Golgi method, Lab. Invest., 1, 345
Peters A., 1964, Observations on the connections between myelin sheaths and glial cells in the optic nerve of young rats, J. Anat., 98, 125
Peters A., 1969, The ratio between myelin segments and oligodendrocytes in the optic nerve of the adult rat, Anat. Rec., 163, 243
Ramón y Cajal S.(1909–11)Histologie du Systemème Nerveux Del'homme et des Vertébrés. Consejo Superior de Investigaciones Cientificas Madrid.
Ransom B. R., 1984, The rat optic nerve following enucleation: A pure preparation of mammalian glia, Soc. Neurosci. Abstr., 10, 949