Balance between Neurogenesis and Gliogenesis in the Adult Hippocampus: Role for ReelinZhao S. · Chai X. · Frotscher M.
aInstitut für Anatomie und Zellbiologie und bZentrum für Neurowissenschaften, Albert-Ludwigs-Universität Freiburg, Freiburg, Deutschland
The extracellular matrix protein reelin is essential for the proper radial migration of cortical neurons. In reeler mice lacking reelin, there is a malformation of the radial glial scaffold required for granule cell migration. Immunostaining for glial fibrillary acidic protein (GFAP) reveals abundant radial glial cells with long fibers traversing the granular layer in the wild type, but almost exclusively astrocytes in the reeler mutant. With the concept that radial glial cells are precursors of neurons, we hypothesized that the balance between neurogenesis and gliogenesis is altered in the reeler mutant. To this end, adult reeler mutants and their wild-type littermates were injected with bromodeoxyuridine (BrdU), a marker of newly generated cells. When compared to wild-type animals, we found a reduction in the number of BrdU-labeled cells in the adult reeler dentate gyrus. Moreover, whereas there was a dramatic decrease in the number of newly generated granule cells identified by double labeling for BrdU and NeuN, the number of BrdU-labeled, GFAP-positive astrocytes had increased. Decreased neurogenesis in the adult reeler dentate gyrus was confirmed by immunostaining for doublecortin, a marker of newly generated neurons. These results indicate that adult neurogenesis is altered in the reeler dentate gyrus and that newly generated cells preferentially differentiate into astrocytes.
Institut für Anatomie und Zellbiologie, Albert-Ludwigs-Universität Freiburg
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Received: January 4, 2006
Accepted: March 7, 2006
Number of Print Pages : 7
Number of Figures : 3, Number of Tables : 0, Number of References : 27
Vol. 29, No. 1-2, Year 2007 (Cover Date: December 2006)
Journal Editor: Campagnoni, A.T. (Los Angeles, Calif.)
ISSN: 0378–5866 (print), 1421–9859 (Online)
For additional information: http://www.karger.com/DNE