title: Enriched environment and physical activity stimulate hippocampal but not olfactory bulb neurogenesis.
abstract: Exposure to an enriched environment and physical activity, such as voluntary running, increases neurogenesis of granule cells in the dentate gyrus of adult mice. These stimuli are also known to improve performance in hippocampus-dependent learning tasks, but it is unclear whether their effects on neurogenesis are exclusive to the hippocampal formation. In this study, we housed adult mice under three conditions (enriched environment, voluntary wheel running and standard housing), and analysed proliferation in the lateral ventricle wall and granule cell neurogenesis in the olfactory bulb in comparison to the dentate gyrus. Using bromodeoxyuridine to label dividing cells, we could not detect any difference in the number of newly generated cells in the ventricle wall. When giving the new cells time to migrate and differentiate in the olfactory bulb, we observed no changes in the number of adult-generated olfactory granule cells; however, voluntary running and enrichment produced a doubling in the amount of new hippocampal granule cells. The discrepancy between the olfactory bulb and the dentate gyrus suggests that these living conditions trigger locally through an as yet unidentified mechanism specific to neurogenic signals in the dentate gyrus.
authors.affiliation: Department of Neurology, University of Regensburg, 93053 Regensburg, Germany.
authors.forename: Jason
authors.initials: J
authors.lastname: Brown
authors.forename: Christiana M
authors.initials: CM
authors.lastname: Cooper-Kuhn
authors.forename: Gerd
authors.initials: G
authors.lastname: Kempermann
authors.forename: Henriette
authors.initials: H
authors.lastname: Van Praag
authors.forename: Jürgen
authors.initials: J
authors.lastname: Winkler
authors.forename: Fred H
authors.initials: FH
authors.lastname: Gage
authors.forename: H Georg
authors.initials: HG
authors.lastname: Kuhn
mesh_terms: D000367:Age Factors; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D004779:Environment Design; D005260:Female; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D006799:Housing, Animal; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D009830:Olfactory Bulb / Q000166:cytology / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*