Summary
The structure and organization of axons in the cervical connective of wild-typeDrosophila fruit flies were examined in anticipation of studies of various neurological mutants. Dissected flies were rapid-frozen from the living state against a copper block cooled with liquid helium, freeze-substituted, and prepared for electron microscopic examination of thin sections. These cryotechniques showed new details of the structure of cell organelles and cytoplasm inDrosophila axons. The cytoplasmic matrix of axons and glia consists of a material with a fine granular texture enmeshed in a three-dimensional meshwork of short, fine filaments which vary in shape, size and electron density. No neurofilaments are present, but bundles of microtubules are interwoven into the filamentous matrix of the axoplasm. The round wall of microtubules (27 nm overall diameter) is composed of twelve cylindrical protofilaments with a typical substructural periodicity. Mitochondria frequently make contact with microtubules in both axons and glial processes. A thin layer of electron-dense filamentous matrix, which appears to be an axonal basal lamina, contacts most of the axonal exoplasmic surface, especially that of axons where they are surrounded by processes of glial cells, but is scant wherever single axons are contiguous. Thus, an axonal basal lamina occupies the constricted spaces around axons, where extracellular K+ accumulates during neural activity.
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References
Adelman, W. J., Jr. &Palti, Y. (1972) The role of periaxonal and perineural spaces in modifying ionic flow across neural membranes. InCurrent Topics in Membrane and Transport, Vol. 3 (edited byBronnes, F. &Kleinzeller, A.), pp. 199–234. New York: Academic Press.
Alkon, D. L. &Grossman, Y. (1978) Evidence of nonsynaptic neuronal interaction.Journal of Neurophysiology 41, 640–53.
Amos, L. A. &Klug, A. (1974) Arrangement of subunits in flagellar microtubules.Journal of Cell Science 14, 533–49.
Anderson, M. (1978) A microscopical study of the innervation of flight muscles in the tsetse fly.Journal of Morphology 155, 19–34.
Bennett, M. V. L. (1977) Electrical transmission: a functional analysis and comparison to chemical transmissions. InHandbook of Physiology. The Nervous System (edited byKandel, E.), pp. 357–416. Baltimore: Williams and Wilkins.
Benshalom, G. &Dagan, D. (1981) Electrophysiological analysis of the temperature-sensitive paralyticDrosophila mutant,para ts.Journal of Comparative Physiology 144, 409–17.
Benshalom, G. &Dagan, D. (1985)Drosophila neural pathways — genetic and electrophysiological analysis.Journal of Comparative Physiology 156, 13–23.
Benzer, S. (1973) Genetic dissection of behavior.Scientific American 299, 24–7.
Berthold, C-H. (1978) Morphology of normal peripheral axons. InPhysiology and Pathobiology of Axons (edited byWaxman, S. G.), pp. 3–63. New York: Raven Press.
Bridgman, P. C. &Reese, T. S. (1984) The structure of cytoplasm in directly frozen cultured cells. I. Filamentous meshworks and the cytoplasmic ground substance.Journal of Cell Biology 99, 1655–68.
Burton, P. R. &Hinkley, R. E. (1974) Further electron microscopic characterization of axoplasmic microtubules of the ventral nerve cord of the crayfish.Journal of Submicroscopic Cytology 6, 311–26.
Coggshall, J. C., Boschek, C. B. &Buchner, S. M. (1973) Preliminary investigation on a pair of giant fibers in the central nervous system of dipteran flies.Zeitschrift für Naturforschung 28c, 783–4.
Davison, P. F. &Winslow, P. (1974) The protein subunit of calf brain neurofilament.Journal of Neurobiology 5, 119–33.
Dustin, P. (1984)Microtubules, 2nd edn. Berlin: Springer-Verlag.
Ellisman, M. H. &Porter, K. R. (1980) Microtrabecular structure of the axoplasmic matrix: visualization of cross-linking structures and their distribution.Journal of Cell Biology 87, 464–79.
Erickson, H. (1974) Microtubule surface lattice and unit structure and observations on reassembly.Journal of Cell Biology 60, 153–67.
Frankenheuser, B. &Hodgkin, A. L. (1956) The after effects of impulses in the giant nerve fiber ofLoligo.Journal of Physiology 131, 341–76.
Frish, D. (1969) A photographic reinforcement analysis of neurotubules and cytoplasmic membranes.Journal of Ultrastructure Research 29, 357–72.
Grimstone, A. V. &Klug, A. (1966) Observations on the substructure of flagaellar fibres.Journal of Cell Science 1, 351–62.
Grossman, Y. &Gutnik, M. J. (1981) Extracellular potassium activity during frequency-dependent conduction block of giant axons in the metathoracic ganglion of the cockroach.Brain Research 211, 196–201.
Hall, J. C. (1978) Behavioral analysis inDrosophila mosaics. InResults and Problems in Cell Differentiation, Vol. 9 (edited byGehring, W. J.), pp. 259–305. Berlin, Heidelberg, New York: Springer-Verlag.
Hall, J. &Greenspan, R. (1979) Genetic analysis ofDrosophila neurobiology.Annual Review of Genetics 13, 127–95.
Harvey, D. M. R. (1982) Freeze-substitution.Journal of Microscopy 127, 209–21.
Hengstenberg, R. (1973) The effect of pattern movement on the impulse activity of the cervical connective ofDrosophila melanogaster.Zeitschrift für Naturforschung 28c, 593–6.
Heuser, J. E. &Kirschner, M. W. (1980) Filament organization revealed in platinum replicas of freeze-dried cytoskeletons.Journal of Cell Biology 86, 212–34.
Heuser, J. E., Reese, T. S., Dennis, M. J., Jan, Y., Jan, L. &Evans, L. (1979) Synaptic vesicle exocytosis captured by quick freezing and correlated with quantal transmitter release.Journal of Cell Biology 81, 275–300.
Heuser, J. E., Reese, T. S. &Landis, D. M. D. (1976) Preservation of synaptic structure by rapid freezing.Cold Spring Harbor Symposia on Quantitative Biology 40, 17–24.
Hirokawa, N. (1982) Cross-linker system between neurofilaments, microtubules, and membranous organelles in frog axons revealed by the quick-freeze, deep-etching method.Journal of Cell Biology 94, 129–42.
Hotta, Y. &Benzer, S. (1970) Genetic dissection ofDrosophila nervous system by means of mosaics.Proceedings of the National Academy of Sciences USA 67, 1480–7.
Hotta, Y. &Benzer, S. (1972) Mapping of behavior inDrosophila mosaics.Nature 240, 527–35.
Ikeda, K. &Kaplan, W. D. (1970) Patterned neural activity of a mutantDrosophila melanogaster.Proceedings of the National Academy of Sciences USA 66, 765–72.
Ikeda, K., Koenig, J. H. &Tsuruhara, T. (1980) Organization of identified axons innervating the dorsal longitudinal flight muscle ofDrosophila melanogaster.Journal of Neurocytology 9, 799–823.
Katz, B. &Schmitt, D. H. (1940) Electrical interaction between two adjacent nerve fibers.Journal of Physiology 97, 471–88.
King, D. G. (1983) Evolutionary loss of a neural pathway from the nervous system of a fly (Glossina morsitans/Diptera).Journal of Morphology 175, 27–32.
King, D. G. &Valentino, K. L. (1983) On neuronal homology: a comparison of similar axons inMusca, Sarcophaga andDrosophila (Diptera: Schizophera).Journal of Comparative Neurology 219, 1–9.
King, D. G. &Wyman, R. J. (1980) Anatomy of the giant fibre pathway inDrosophila. I. Three thoracic components of the pathway.Journal of Neurocytology 9, 753–70.
Kosaka, T. &Ikeda, K. (1983) Possible temperature-dependent blockage of synaptic vesicle recycling induced by a single gene mutation inDrosophila.Journal of Neurobiology 14, 207–25.
Lane, N. J. (1974) The organization of insect nervous system. InInsect Neurobiology (edited byTreherne, J. E.), pp. 1–71. Amsterdam, Oxford: North Holland Publishing Company.
Lane, N. J. &Treherne, J. E. (1970) Lanthanum staining of neurotubules in axons from cockroach ganglia.Journal of Cell Science 7, 217–31.
McCann, F. V. &Boettiger, E. G. (1961) Studies of the flight mechanism of insects. I. The electrophysiology of fibrillar flight muscle.Journal of General Physiology 45, 125–42.
Miller, K. R., Prescott, C. S., Jacobs, T. L. &Lassignal, N. L. (1983) Artifacts associated with quick-freezing and freeze-drying.Journal of Ultrastructure Research 82, 123–33.
Nakajima, Y. &Reese, T. S. (1983) Inhibitory and excitatory synapses in crayfish stretch receptor organs studied with direct rapid-freezing and freeze-substitution.Journal of Comparative Neurology 213, 66–73.
Orkand, R. K. (1980) Extracellular potassium accumulation in the nervous system.Federation Proceedings 39, 1515–8.
Ornberg, R. L. &Reese, T. S. (1979) Artifacts of freezing inLimulus amebocytes. InFreeze Fracture: Methods, Artifacts and Interpretations (edited byRash, J. E. &Hudson, C. S.), pp. 89–97. New York: Raven Press.
Ornberg, R. L. &Reese, T. S. (1980) A freeze-substitution method for localizing divalent cations: examples from secretory systems.Federation Proceedings 39, 2802–8.
Ornberg, R. L. &Reese, T. S. (1981) Beginning of exocytosis captured by rapid-freezing ofLimulus amebocytes.Journal of Cell Biology 90, 40–54.
Pak, W. L. &Pinto, L. H. (1976) Genetic approach to the study of the nervous system.Annual Review of Biophysics and Bioengineering 5, 397–448.
Peters, A., Palay, S. L. &Webster, H. deF. (1976)The Fine Structure of the Nervous System: The Neurons and Supporting Cells. Philadelphia: W. B. Saunders.
Pinto da Silva, P. &Kachar, B. (1980) Quick freezing vs chemical fixation: capture and identification of membrane fusion intermediates.Cell Biology International Reports 4, 625–40.
Poodry, C. A. &Edgar, L. (1979) Reversible alterations in the neuromuscular junction ofDrosophila melanogaster bring a temperature-sensitive mutationshibire.Journal of Cell Biology 81, 520–7.
Porter, K. R. (1978) Organization in the structure of the cytoplasmic ground substance. InNinth International Congress on Electron Microscopy, Toronto, Vol. III, pp. 627–39.
Rash, J. E. (1983) The rapid-freeze technique in neurobiology.Trends in Neurosciences 6, 208–12.
Rees, R. P. &Reese, T. S. (1981) New structural features of freeze-substituted neuritic growth cones.Neuroscience 6, 247–54.
Saito, K. &Hama, K. (1982) Structural diversity of microtubules in the supporting cells of sensory epithelium of guinea pig organ of Corti.Journal of Electron Microscopy 31, 278–81.
Schnapp, B. J. &Reese, T. S. (1982) Cytoplasmic structure in rapid-frozen axons.Journal of Cell Biology 94, 667–79.
Shafiq, A. S. (1964) An electron microscopical study of the innervation and sarcoplasmic reticulum of the fibrillar flight muscle ofDrosophila melanogaster.Quarterly Journal of Microscopic Science 105, 1–6.
Smith, J. E. &Reese, T. S. (1980) Use of aldehyde fixatives to determine the rate of synaptic transmitter release.Journal of Experimental Biology 89, 19–29.
Stearns, M. E. (1982) High voltage electron microscopy studies of axoplasmic transport in neurons: a possible regulatory role for divalent cations.Journal of Cell Biology 92, 765–76.
Suzuki, D. T. (1974) Behavior inDrosophila melanogaster. A geneticist's view.Canadian Journal of Genetics and Cytology 16, 713–35.
Tilney, L. G., Bryan, J., Bush, D. J., Fujiwara, K., Mooseker, M. S., Murphy, D. B. &Snyder, D. H. (1973) Microtubules: evidence for 13 protofilaments.Journal of Cell Biology 59, 267–75.
Tsukita, S., Usukura, J., Tsukita, S. &Ishikawa, H. (1982) The cytoskeleton in myelinated axons: a freeze-etch replica study.Neuroscience 7, 2135–47.
Van Harreveld, A., Crowell, J. &Malhotra, S. K. (1965) A study of extracellular space in central nervous tissue by freeze-substitution.Journal of Cell Biology 25, 117–37.
Wolosewick, J. J. &Porter, K. R. (1976) Stereo high-voltage electron microscopy of whole cells of the human diploid cell line WI-38.American Journal of Anatomy 146, 303–24.
Wolosewick, J. J. &Porter, K. R. (1979) Microtrabecular lattice of the cytoplasmic ground substance. Artifact or reality.Journal of Cell Biology 82, 114–39.
Yarom, Y. &Spira, M. E. (1982) Extracellular potassium ions mediate specific neuronal interaction.Science 216, 80–2.
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Benshalom, G., Reese, T.S. Ultrastructural observations on the cytoarchitecture of axons processed by rapid-freezing and freeze-substitution. J Neurocytol 14, 943–960 (1985). https://doi.org/10.1007/BF01224806
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DOI: https://doi.org/10.1007/BF01224806