title: The Role of the Microenvironmental Niche in Declining Stem-Cell Functions Associated with Biological Aging.
abstract: Aging is strongly correlated with decreases in neurogenesis, the process by which neural stem and progenitor cells proliferate and differentiate into new neurons. In addition to stem-cell-intrinsic factors that change within the aging stem-cell pool, recent evidence emphasizes new roles for systemic and microenvironmental factors in modulating the neurogenic niche. This article focuses on new insights gained through the use of heterochronic parabiosis models, in which an old mouse and a young circulatory system are joined. By studying the brains of both young and old mice, researchers are beginning to uncover circulating proneurogenic "youthful" factors and "aging" factors that decrease stem-cell activity and neurogenesis. Ultimately, the identification of factors that influence stem-cell aging may lead to strategies that slow or even reverse age-related decreases in neural-stem-cell (NSC) function and neurogenesis.
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: DeCarolis
authors.affiliation: Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Kirby
authors.affiliation: Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305 Center for Tissue Regeneration, Repair, and Restoration, Veterans Administration, Palo Alto Health Care Systems, Palo Alto, California 94304.
authors.forename: Tony
authors.initials: T
authors.lastname: Wyss-Coray
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305 Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305.
authors.forename: Theo D
authors.initials: TD
authors.lastname: Palmer
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology*; D006801:Humans; D051379:Mice; D058953:Neural Stem Cells / Q000502:physiology*; D055495:Neurogenesis; D009474:Neurons / Q000502:physiology; D010227:Parabiosis; D055153:Stem Cell Niche / Q000502:physiology*