Experimental Manipulation and Morphometric Analysis of Neural Tube Development

  • Mary E. Desmond
  • Patricia A. Haas
Part of the Methods in Molecular Biology™ book series (MIMB, volume 136)

Abstract

The morphology of the early embryonic vertebrate neural tube differs significantly in the brain and spinal cord anlages. Although both are hollow, the early embryonic brain has a larger cavity volume than tissue volume, whereas the spinal cord consists mostly of tissue and a reduced cavity. Growth of these two central nervous system (CNS) anlages therefore requires attention to both fluid and tissue dynamics as well as to tissues outside the CNS, namely the mesenchyme and skin ectoderm. By measuring the volumes of the tissue and cavity compartments of the brain as well as the cell number, rates of DNA synthesis, and mitosis of the neuroepithelium, it is possible to gain a better understanding of the cellular mechanisms involved in growth of the CNS. Volume assessment over time gives us an idea of change in size, whereas the details of cell behavior tell us how this changes occurs. Collectively, these changes in size and shape of the CNS are analyzed by morphometric techniques that, to date, have required performing measurements on serial sections of properly fixed and prepared embryos. Most likely in the near future, imaging techniques utilizing magnetic resonance proper will obviate the need to fix and section embryos. However, because these sophisticated imaging techniques are not yet available to mainstream research laboratories, this chapter focuses on performing morphometrics on sectioned and whole embryos.

Keywords

Mold Shrinkage Assure Dehydration Sponge 

References

  1. 1.
    Desmond, M. E. and Jacobson, A. G. (1977) Embryonic brain enlargement requires cerebrospinal fluid pressure. Dev. Biol. 57, 188–198.PubMedCrossRefGoogle Scholar
  2. 2.
    Weibel, E. R. (1979) Stereological Methods. Vol. 1. Practical Methods for Biological Morphometry. Academic, New York.Google Scholar
  3. 3.
    Desmond, M. E. and O’Rahilly, R. (1981) The growth of the human brain during the embryonic period proper. 1. Linear axes. Anat. Embryol. 162, 137–151.PubMedCrossRefGoogle Scholar
  4. 4.
    Summerbell, D. (1976) A descriptive study of the rate of elongation and differentiation of the skeleton of the developing chick wing. J. Embryol. Exp. Morphol. 35, 241–260.PubMedGoogle Scholar
  5. 5.
    Desmond, M. E., New, M. S., Martin, B. G., and Fleischman, W. M. (1990) A rapid reliable calculation of brain expansion in living chick embryos to reflect fluid transport across the neuroepithelium. Anat. Rec. 226, 34A.Google Scholar
  6. 6.
    Gibson, K. D., Segen, B. J., and Doller, H. J. (1979) B-D-xylosides cause abnormalities of growth and development in chick embryos. Nature 273, 151–157.CrossRefGoogle Scholar
  7. 7.
    Desmond, M. E. and Field, M. C. (1990) Bubble-like minispheres of avian embryonic neuroepithelium: a model for studying fluid transport. Soc. Neurosci. Abstr. 16, 1150A.Google Scholar
  8. 8.
    Hamburger, V. and Hamilton, H. (1951) A series of normal stages in the development of the chick embryo. J. Morphol. 88, 49–92.CrossRefGoogle Scholar
  9. 9.
    Pacheco, M. A., Marks, R. W., Schoenwolf, G. C., and Desmond, M. E. (1986) Quantification of the initial phases of rapid brain enlargement in the chick embryo. Am. J. Anat. 175, 403–411.PubMedCrossRefGoogle Scholar
  10. 10.
    Kallen, B. (1961) Studies on cell proliferation in the brain of chick embryos with special reference to the mesenchephalon. Z. Anat. Entwicklungsgesch. 122, 388–401.PubMedCrossRefGoogle Scholar
  11. 11.
    Cowan, W., Martin, A., and Wenger, E. (1968) Mitotic patterns in the optic tectum of the chick during normal development and after early removal of the optic vesicle. J. Exp. Zool. 169, 71–92.PubMedCrossRefGoogle Scholar
  12. 12.
    Wilson, D. B. (1973) Chronological changes in the cell cycle of chick neuroepithelial cells. J. Embryol. Exp. Morphol. 29, 745–751.PubMedGoogle Scholar
  13. 13.
    Burton, K. (1956) A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid. Biochem. J. 62, 315–323.PubMedGoogle Scholar
  14. 14.
    Giles, K. and Myers, A. (1965) An improved diphenylamine method for the estimation of deoxyribonucleic acid. Nature 206, 93.CrossRefGoogle Scholar
  15. 15.
    Dische, Z. (1930) Ueber einige neue characteristische farbreaktionen der thymonukleinsaure und eine mikromethode zur bestimmung derselben in tierischen organen mit hilfe dieser reaktionen. Mikrochemie 8, 4–32.CrossRefGoogle Scholar
  16. 16.
    Desmond, M. E. (1985) Reduced number of brain cells in so-called neural overgrowth. Anat. Rec. 212, 195–198.PubMedCrossRefGoogle Scholar
  17. 17.
    Wilson, D. B. (1974) The cell cycle of ventricular cells in the overgrown optic tectum. Brain Res. 69, 41–48.PubMedCrossRefGoogle Scholar
  18. 18.
    Davidson, J., Leslie, I., Smellie, R., and Thomson, R. (1950) Chemical changes in the developing chick embryo related to the desoxyribonucleic acid content of the nucleus. Biochem. J. 47, XL.Google Scholar
  19. 19.
    Hyatt, G. A. and Beebe, D. C. (1992) Use of a double-label method to detect rapid change in the rate of cell proliferation. J. Histochem. Cytochem. 40, 619–627.PubMedGoogle Scholar

Copyright information

© Humana Press Inc. 2000

Authors and Affiliations

  • Mary E. Desmond
    • 1
  • Patricia A. Haas
    • 1
  1. 1.Department of BiologyVillanova UniversityVillanova

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