Autoradiographic and histological studies of postnatal neurogenesis. I. A longitudinal investigation of the kinetics, migration and transformation of cells incoorporating tritiated thymidine in neonate rats, with special reference to postnatal neurogenesis in some brain regions

Authors

  • Joseph Altman,

    1. Psychophysiological Laboratory, Massachusetts Institute of Technology, Cambridge, Maasachusetts
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    • This research program is supported by the U. S. Atomic Energy Commission. The assistance of Elizabeth C. Altman. William J. Anderson and Virginia Hanson is gratefully acknowledged.

  • Gopal D. Das

    1. Psychophysiological Laboratory, Massachusetts Institute of Technology, Cambridge, Maasachusetts
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Abstract

Neonate rats were injected systemically with thymidine-H3 and killed after different periods of survival. Cell proliferation, migration and transformation in the brain were studied autoradiographically. It was established that cells multiplying in the ependymal and subependymal walls of the olfactory ventricle migrate outward into the olfactory bulb, where they become differentiated into granule cells. These postnatally formed granule cells contribute to the formation of the granular and several other layers of the olfactory bulb. Cells multiplying at a high rate in the wall of the lateral ventricle migrate to the hippocampus and contribute to the formation of the granule cells in the granular layer of the dentate gyrus. Cells multiplying at a high rate in the external and internal granular layers of the cerebellum become differentiated into granule cells, and, to a lesser extent, other types of nerve cells of the cerebellar cortex. Evidence was also obtained of the postnatal origin of many of the granule cells of the cochlear nucleus. Postnatal neurogenesis is restricted to these short-axoned granule cells or microneurons; the long-axoned nerve cells or macroneurons of the brain are formed prenatally.

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