The cortical plate and molecular layer of the late rat fetus

  • Alan Peters
  • Martin Feldman
Article

Summary

In the cortical plate of the late prenatal rat fetus the neuroblasts can be considered to be of three types: mature neuroblasts which are prominent in the lower levels of the cortical plate and have some of the cytoplasmic and nuclear features of neurons, immature neuroblasts that have recently completed their migrations into the cortical plate, and migrating neuroblasts that are still in the process of moving to their definitive positions. Both of these latter types have darker cytoplasm than the mature neuroblasts. All of the neuroblasts have an apical process that extends directly towards the pial surface of the cortical plate and a basal process that is directed towards the intermediate zone of the developing hemisphere. In Golgi preparations some of these basal processes, particularly those of neuroblasts situated in the lower levels of the cortical plate, seem to have formed axons that pass through the intermediate zone to enter the developing white matter, in which they turn at right angles away from, and rarely toward, the midline. Other elements traversing the cortical plate are the ascending processes of spongioblasts that branch in the molecular layer and form expansions at the surface of the hemisphere. In the molecular layer the spongioblast terminal branches intertwine with the apical tufts of the ascending neuroblast processes and with thin processes that have the features of axons, to form a loose neuropil. In the cortical plate the spongioblast processes are usually closely and preferentially surrounded by the dark migrating neuroblasts and by the immature neuroblasts. Both of these latter may partially encompass spongioblast processes. Hence it is concluded that the spongioblast processes act as guides along which the migrating neuroblasts ascend through the cortical plate.

Key words

CNS Cortical plate Neuroblasts Rat 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Adinolfi, A.M.: The postnatal development of synaptic contacts in the cerebral cortex. In: Brain, development and behavior (eds. M.B. Sterman, D.J. McGinty and A.M. Adinolfi), p. 71–88. New York: Academic Press 1971.Google Scholar
  2. Aghajanian, G.K. Bloom, F.E.: The formation of synaptic junctions in developing rat brain—a quantitative electron microscopic study. Brain Res. 6, 716–727 (1967).Google Scholar
  3. Angevine, J.B., Sidman, R.L.: Autoradiographic study of cell migration during histiogenesis of cerebral cortex in the mouse. Nature (Lond.) 192, 766–768 (1961).Google Scholar
  4. Armstrong-James, M.A., Williams, T.D.: Postnatal development of the direct response in the rat. J. Physiol. (Lond.) 168, 19 P (1963).Google Scholar
  5. Armstrong-James, M.A., Williams, T.D.: Differences in the direct cortical response to unifocal stimuli during the post-natal development of the rat cerebral cortex. J. Physiol. (Lond.) 170, 15 P. (1964).Google Scholar
  6. Berry, M., Rogers, A.W.: The migration of neuroblasts in the developing cerebral cortex. J. Anat. (Lond.) 99, 691–709 (1965).Google Scholar
  7. Berry, M., Rogers, A.W.: Histogenesis of mammalian neocortex. In: Evolution of the forebrain (eds. Hassler, R. and Stephen, H.), p. 197–205 New York: Plenum Press 1967.Google Scholar
  8. Bodian, D.: Development of fine structure of spinal cord in monkey fetuses. I. The motoneuron neuropil at the time of onset of reflex activity. Bull. Johns Hopk. Hosp. 119, 129–149 (1966).Google Scholar
  9. Butler, A.B., Caley, D.W.: An ultrastructural and radiographic study of the migrating neuroblast in the hamster neocortex. Brain Res. 44, 83–97 (1972).Google Scholar
  10. Caley, D.W., Maxwell, D.S.: An electron microscopic study of neurons during postnatal development of the rat cerebral cortex. J. comp. Neurol. 133, 17–44 (1968a).Google Scholar
  11. Caley, D.W., Maxwell, D.S.: An electron microscopic study of the neuroglia during postnatal development of the rat cerebrum. J. comp. Neurol. 133, 45–70 (1968b).Google Scholar
  12. Chow, K.L., Leiman, A.L. (eds.): The structural and functional organization of the neocortex. Neurosciences Research Program Bulletin, 8, No 2 (1970).Google Scholar
  13. Del Cerro, M.P., Snider, R.S.: Studies on the developing cerebellum. Ultrastructure of the growth cones. J. comp. Neurol. 133, 341–362 (1968).Google Scholar
  14. Eayrs, J.T., Goodhead, B.: Postnatal development of the cerebral cortex in the rat. J. Anat. (Lond.) 93, 385–402 (1959).Google Scholar
  15. Fleischhauer, K., Petsche, H., Wittowski, W.: Vertical bundles of dendrites in the neocortex. Z. Anat. Entwickl.-Gesch. 127, 213–223 (1972).Google Scholar
  16. Hicks, S.P., D'Amato, C.J.: Cell migration to the isocortex in the rat. Anat. Rec. 160, 619–634 (1968).Google Scholar
  17. Hinds J.W., Hinds, P.L.: Reconstruction of dendritic growth cones in neonatal mouse olfactory bulb. J. Neurocytol. 1, 169–187 (1972).Google Scholar
  18. Holmes, R.L., Berry, M.: Electron-microscopic studies on developing foetal cerebral cortex of the rat. In: Evolution of the forebrain (eds. Hassler, R. and Stephen, H.), p. 206–212 New York: Plenum Press 1967.Google Scholar
  19. Johnson, R., Armstrong-James, M.: Morphology of superficial postnatal cerebral cortex with special reference to synapses. Z. Zellforsch. 110, 540–558 (1970).Google Scholar
  20. Kawana, E., Sandri, C., Akert, K.: Ultrastructure of growth cones in the cerebellar cortex of the neonatal rat and cat. Z. Zellforsch. 115, 284–298 (1971).Google Scholar
  21. Langman, J., Welch, G.W.: Excess vitamin A and development of the cerebral cortex. J. comp. Neurol. 131, 15–26 (1967).Google Scholar
  22. Long, J.A., Burlingame, P.L.: The development of external form of the rat, with some observations on the origin of the extraembryonic coelom and foetal membranes. Univ. Calif. Publ. Zool. 43, 143–155 (1938).Google Scholar
  23. Marin-Padilla, M.: Prenatal and early postnatal ontogenesis of the human motor cortex: A Golgi study. I. The sequential development of the cortical layers. Brain Res. 23, 167–183 (1970).Google Scholar
  24. Marin-Padilla, M.: Early prenatal ontogenesis of the cerebral cortex (neocortex) of the cat (Felis domestica): A Golgi study. Z. Anat. Entwickl.-Gesch. 134, 117–145 (1971).Google Scholar
  25. Meller, K., Breipohl, W., Glees, P.: The cytology of the developing molecular layer of mouse motor cortex.: An electron microscopical and a Golgi-impregnation study. Z. Zellforsch. 86, 171–183 (1966).Google Scholar
  26. Meller, K., Breipohl, W., Glees, P.: Synaptic organization of the molecular layer and the outer granular layer in the motor cortex in the white mouse during postnatal development.: A Golgi—and electron microscopical study. Z. Zellforsch. 92, 217–231 (1968).Google Scholar
  27. Morest, D.K.: A study of neurogenesis in the forebrain of opossum pouch young. Z. Anat. Entwickl.-Gesch. 130, 265–305 (1970).Google Scholar
  28. Mountcastle, V.B.: Modality and topographic properties of single neurons of the cat's somatic sensory cortex. J. Neurophysiol. 20, 408–434 (1957).Google Scholar
  29. Nauta, W.J.H., Bucher, V.W.: Efferent connections of the striate cortex in the albino rat. J. comp. Neurol. 100, 257–286 (1954).Google Scholar
  30. Palay, S.L., Sotelo, C., Peters, A., Orkand, P.M.: The axon hillock and the initial segment. J. Cell Biol. 38, 193–201 (1968).Google Scholar
  31. Peters, A., Kaiserman-Abramof, I.R.: The small pyramidal neuron of the rat cerebral cortex: The perikaryon, dendrites and spines. Amer. J. Anat. 127, 321–356 (1970).Google Scholar
  32. Peters, A., Proskauer, C.C., Kaiserman-Abramof, I.R.: The small pyramidal neuron of the rat cerebral cortex: the axon hillock and initial segment. J. Cell Biol. 39, 604–619 (1968).Google Scholar
  33. Peters, A., Walsh, T.M.: A study of the organization of apical dendrites in the somatic sensory cortex of the rat. J. comp. Neurol. 144 253–268 (1972).Google Scholar
  34. Rakic, P.: Guidance of neurons migrating to the fetal monkey neocortex. Brain Res. 33, 471–476 (1971).Google Scholar
  35. Rakic, P.: Mode of cell migration to the superficial layer of fetal monkey cortex. J. comp. Neurol. 145, 61–84 (1972).Google Scholar
  36. Shimada, M., Langman, J.: Cell proliferation, migration and differentiation in the cerebral cortex of the golden hamster. J. comp. Neurol. 139, 227–244 (1970).Google Scholar
  37. Stensaas, L.J.: The development of hippocampal and dorsolateral pallial regions of the cerebral hemisphere in fetal rabbits. I. Fifteen millimeter stage; Spongioblast morphology. J. comp. Neurol. 129, 59–70 (1967a).Google Scholar
  38. Stensaas, L.J.: The development of hippocampal and dorsolateral pallial regions of the cerebral hemisphere in fetal rabbits. II. Twenty millimeter stage; neuroblast morphology. J. comp. Neurol. 129, 71–84 (1967b).Google Scholar
  39. Stensaas, L.J.: The development of hippocampal and dorsolateral pallial regions of the cerebral hemisphere in fetal rabbits. III. Twenty-nine millimeter stage; marginal lamina. J. comp. Neurol. 130, 149–162 (1967c).Google Scholar
  40. Stensaas, L.J.: The development of hippocampal and dorsolateral pallial regions of the cerebral hemisphere in fetal rabbits. IV. Forty-one millimeter stage; intermediate lamina. J. comp. Neurol. 131, 409–422 (1967d).Google Scholar
  41. Stensaas, L.J.: The development of hippocampal and dorolateral pallial regions of the cerebral hemisphere in fetal rabbits. V. Sixty millimeter stage; glial cell morphology. J. comp. Neurol. 131, 423–436 (1967e).Google Scholar
  42. Stensaas, L.J., Stensaas, S.: an electron microscope study of the cells in the matrix and intermediate laminae of the cerebral hemisphere of the 45 mm rabbit embryo. Z. Zell-forsch. 91, 341–365 (1968).Google Scholar
  43. Tennyson, V.M.: The fine structure of the axon and growth cone of the dorsal root neuroblast of the rabbit embryo. J. Cell Biol. 44, 62–79 (1970).Google Scholar
  44. Valverde, F.: Studies on the Piriform Lobe. Cambridge: Harvard University Press 1965.Google Scholar
  45. Voeller, K., Pappas, G.D., Purpura, D.P.: Electron microscope study of development of cat superficial neocortex. Exp. Neurol. 7, 107–130 (1963).Google Scholar
  46. Von Bonin, G., Mehler, W.R.: On columnar arrangement of nerve cells in cerebral cortex. Brain Res. 27, 1–10 (1971).Google Scholar
  47. Welker, C.: Microelectrode delineation of fine grain somatotopic organization of Sml cerebral neocortex in albino rats. Brain Res. 26, 259–275 (1971).Google Scholar
  48. Woolsey, T.H., Van der Loos H.: The structural organization of layer IV in the somato sensory region (S1) of mouse cerebral cortex. Brain Res. 17, 205–242 (1970).Google Scholar

Copyright information

© Springer-Verlag 1973

Authors and Affiliations

  • Alan Peters
    • 1
  • Martin Feldman
    • 1
  1. 1.Department of AnatomyBoston University Medical SchoolBostonUSA

Personalised recommendations