title: Stem- and progenitor cell proliferation in the dentate gyrus of the reeler mouse.
abstract: Adult hippocampal neurogenesis has been implicated in hippocampus-dependent learning and memory. Furthermore, the decline of neurogenesis accompanying aging could be involved in age-related cognitive deficits. It is believed that the neural stem cell niche comprises a specialized microenvironment regulating stem cell activation and maintenance. However, little is known about the significance of the extracellular matrix in controlling adult stem cells. Reelin is a large glycoprotein of the extracelluar matrix known to be of crucial importance for neuronal migration. Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation. Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin. We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells. A detailed analysis of dividing Type 1, type 2 and type 3 cells indicated that once a stem cell is recruited for proliferation, the progression to the next progenitor stage as well as the number of mitotic cycles is not altered in reeler. Our data point to a role for Reelin in either regulating stem cell quiescence or maintenance.
authors.affiliation: Center for Neuroscience, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 23, D-79104, Freiburg, Germany.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Sibbe
authors.affiliation: Center for Neuroscience, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 23, D-79104, Freiburg, Germany.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Kuner
authors.affiliation: Institute of Physiology, University of Freiburg, Hermann-Herder-Str. 7, D-79104, Freiburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Althof
authors.affiliation: Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg, Falkenried 94, D-20251, Hamburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Frotscher
mesh_terms: D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D018891:Dentate Gyrus / Q000166:cytology* / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D007395:Interneurons / Q000378:metabolism*; D008297:Male; D051379:Mice; D008938:Mitosis; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000502:physiology*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases