Summary
The intercellular “spaces” of rat cerebral cortex are filled with a dense material, demonstrable by electron microscopy. This intercellular substance is in part preserved by chemical fixation with formaldehyde and osmium tetroxide but is solubilized and largely lost during subsequent dehydration with ethyl alcohol. Dehydration with acetone or Durcupan favors the preservation of the intercellular substance, which is preserved also by freezing and drying. Whether the intercellular substance demonstrated here is part of the outer leaflets of apposing plasma membranes (“glycocalyx”) or truly an intercellular substance similar to connective tissue ground substance is not known. The probability of the latter is discussed with regard to proposed physiological mechanisms.
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References
Bennett, H. S.: Morphological aspects of extracellular polysaccharides. J. Histochem. Cytochem. 11, 14–23 (1963).
Bondareff, W.: The extracellular compartment of the cerebral cortex. Anat. Rec. 152, 119–128 (1965).
Caulfield, J. B.: Effects of varying the vehicle of OsO4 in tissue fixation. J. biophys. biochem. Cytol. 3, 827–830 (1957).
Clausen, J., and A. Hansen: Acid mucopolysaccharides of human brain. J. Neurochem. 10, 165–168 (1963).
Eccles, J. C.: The physiology of synapses. New York: Academic Press 1964.
Farquhar, M. G., and G. E. Palade: Junctional complexes in various epithelia. J. Cell Biol. 17, 375–412 (1963).
Fernandez-Moran, H., and J. B. Finean: Electron microscope and low angle X-ray diffration studies of the nerve myelin sheath. J. biophys. biochem. Cytol. 3, 725–748 (1957).
Fraenkel-Conrat, H.: The action of 1,2-epoxides on proteins. J. Biochem. 154, 227–238 (1944).
Glauert, A. M., G. E. Rogers, and R. H. Glauert: Araldite as an embedding medium for electron microscopy. J. biophys. biochem. Cytol. 4, 191–194 (1958).
Gray, E. G.: Tissue of the central nervous system. In: “Electron microscopic anatomy”, p. 412–413 (Ed. Kurtz, S. M.). New York: Academic Press 1964.
Hertz, L.: Possible role of neuroglia: a potassium-mediated neuronal-neuroglial-neuronal impulse transmission system. Nature (Lond.) 206, 1091–1094 (1965).
Horstmann, E., u. H. Meves: Die Feinstruktur des molekularen Rindengraues und ihre physiologische Bedeutung. Z. Zellforsch. 49, 569–604 (1959).
Karlsson, U., and L. Schultz: Fixation of the central nervous system for electron microscopy by aldehyde perfusion. I. Preservation with aldehyde perfusates versus direct perfusion with osmium tetroxide with special reference to membranes and the extracellular space. J. Ultrastruc. Res. 12, 160–186 (1965).
Luse, S. A.: Electron microscopic observation of the central nervous system. J. biophys. biochem. Cytol. 2, 531–542 (1956).
Manoranjan, S., and B. K. Bachhawat: The distribution and variation with age of different uronic acid-containing mucopolysaccharides in brain. J. Neurochem. 12, 519–525 (1965).
Mathews, M. B.: Sodium chondroitin sulfate-protein complexes of cartilage. III. Preparation from shark. Biochim. biophys. Acta (Amst.) 58, 92–101 (1962).
: Structural factors in cation binding to anionic polysaccharides of connective tissue. Arch. Biochem. 104, 394–404 (1964).
Nicholls, J. G., and S. W. Kuffler: Extracellular space as a pathway for exchange between blood and neurons in the central nervous system of the leech: ionic composition of glial cells and neurons. J. Neurophysiol. 27, 646–671 (1964).
Palay, S. L., S. M. McGee-Russel, S. Gordon jr., and M. A. Grillo: Fixation of neural tissues for electron microscopy by perfusion with solutions of osmium tetroxide. J. Cell Biol., 12, 385–410 (1962).
Peters, A.: Plasma membrane contacts in the central nervous system. J. Anat. (Lond.) 96, 232–248 (1962).
Reynolds, E. S.: The use of lead citrate at high pH as an electron opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Robertson, J. D.: Unit membranes: A review with recent new studies of experimental alterations and a new subunit structure in synaptic membranes. In: Cellular membranes in development, Proceedings of the XXII Symposium of the Society for the Study of Development and Growth, p. 1–82 (Ed. Locke, M.). New York: Academic Press 1964.
Schultz, R. L., E. A. Maynard, and D. C. Pease: Electron microscopy of neurons and neuroglia of cerebral cortex and corpus callosum. Amer. J. Anat. 100, 369–408 (1957).
Sjöstrand, F. S.: Electron microscopy of myelin and of nerve cells and tissues. In: Modern scientific aspects of neurology, p. 188–231 (Ed. Cumings, J. N.). London: Edward Arnold 1960.
Stäubli, W.: A new embedding technique for electron microscopy, combining a water-soluble epoxy resin (Durcupan) with water-insoluble araldite. J. Cell Biol. 16, 197–201 (1963).
Stoekenius, W.: The molecular structure of lipid-water systems and cell membrane models studied with the electon microscope. In: The interpretation of ultrastructure, p. 349–368 (Ed. Harris, R. C. H.), New York: Academic Press 1962.
Szabo, M. M., and E. Roboz-Einstein: Acidic polysaccharides in the central nervous system. Arch. Biochem. 98, 406–412 (1962).
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This work was supported by USPHS Research Grants NB 05175 and AM 06998.
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Bondareff, W. Electron microscopic evidence for the existence of an intercellular substance in rat cerebral cortex. Zeitschrift für Zellforschung 72, 487–495 (1966). https://doi.org/10.1007/BF00319254
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DOI: https://doi.org/10.1007/BF00319254