Multi-directional differentiation of doublecortin- and NG2-immunopositive progenitor cells in the adult rat neocortex in vivo

Authors

  • Yasuhisa Tamura,

    1. Department of Anatomy and Cell Science, KMU 21C COE Project, Kansai Medical University, 10–15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan
    2. Molecular Imaging Research Program, RIKEN Frontier Research System, 6-7-3 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
    3. Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
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  • Yosky Kataoka,

    1. Department of Anatomy and Cell Science, KMU 21C COE Project, Kansai Medical University, 10–15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan
    2. Molecular Imaging Research Program, RIKEN Frontier Research System, 6-7-3 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
    3. Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
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  • Yilong Cui,

    1. Department of Anatomy and Cell Science, KMU 21C COE Project, Kansai Medical University, 10–15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan
    2. Molecular Imaging Research Program, RIKEN Frontier Research System, 6-7-3 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
    3. Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
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  • Yasuharu Takamori,

    1. Department of Anatomy and Cell Science, KMU 21C COE Project, Kansai Medical University, 10–15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan
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  • Yasuyoshi Watanabe,

    1. Molecular Imaging Research Program, RIKEN Frontier Research System, 6-7-3 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
    2. Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
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  • Hisao Yamada

    1. Department of Anatomy and Cell Science, KMU 21C COE Project, Kansai Medical University, 10–15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan
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Dr Y. Kataoka, as above.3
E-mail: kataokay@med.osaka-cu.ac.jp

Abstract

In the adult mammalian brain, multipotent stem or progenitor cells involved in reproduction of neurons and glial cells have been well investigated only in very restricted regions; the subventricular zone of the lateral ventricle and the dentate gyrus in the hippocampal formation. In the neocortex, a series of in vitro studies has suggested the possible existence of neural progenitor cells possessing neurogenic and/or gliogenic potential in adult mammals. However, the cellular properties of the cortical progenitor cells in vivo have not been fully elucidated. Using 5′-bromodeoxyuridine labeling and immunohistochemical analysis of cell differentiation markers, we found that a subpopulation of NG2-immunopositive cells co-expressing doublecortin (DCX), an immature neuron marker, ubiquitously reside in the adult rat neocortex. Furthermore, these cells are the major population of proliferating cells in the region. The DCX(+)/NG2(+) cells reproduced the same daughter cells, or differentiated into DCX(+)/NG2(–) (approximately 1%) or DCX(–)/NG2(+) (approximately 10%) cells within 2 weeks after cell division. The DCX(+)/NG2(–) cells were also immunopositive for TUC-4, a neuronal linage marker, suggesting that these cells were committed to neuronal cell differentiation, whereas the DCX(–)/NG2(+) cells showed faint immunoreactivity for glutathione S-transferase (GST)-pi, an oligodendrocyte lineage marker, in the cytoplasm, suggesting glial cell lineage, and thereafter the cells differentiated into NG2(–)/GST-pi(+) mature oligodendrocytes after a further 2 weeks. These findings indicate that DCX(+)/NG2(+) cells ubiquitously exist as ‘multipotent progenitor cells’ in the neocortex of adult rats.

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