title: Exercise enhances the proliferation of neural stem cells and neurite growth and survival of neuronal progenitor cells in dentate gyrus of middle-aged mice.
abstract: Aging is an important determinant of adult hippocampal neurogenesis as the proliferation of neural stem/precursor cells (NSCs) declines dramatically before middle age. Contrary to this, physical exercise is known to promote adult hippocampal neurogenesis. The objective of this study is to investigate the effects of mandatory treadmill running (TR) on neurogenesis, including 1) NSCs proliferation, 2) neurite outgrowth of neuronal progenitor cells, and 3) the survival of newborn neurons in dentate area of middle-aged animals. Compared with 3-mo-old mice, numbers of mitotic cells and neuronal progenitor cells decreased dramatically by middle age and remained at low levels after middle age. Five weeks of TR not only increased NSC proliferation and the number of immature neurons but also promoted the maturation and survival of immature neurons in middle-aged mice. The neurogenic and neurotrophic effects of TR were not due to the reduction of the age-related elevation of serum corticosterone. Significantly, 5 wk of TR restored the age-dependent decline of brain-derived neurotrophic factor and its receptor, TrkB, which are known to promote neuronal differentiation and survival. Taken together, mandatory running exercise alters the brain chemistries of middle-aged animals toward an environment that is favorable to NSC proliferation, survival, and maturation.
authors.affiliation: Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan.
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Wu
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chang
authors.forename: Lung
authors.initials: L
authors.lastname: Yu
authors.forename: Hsiun-ing
authors.initials: HI
authors.lastname: Chen
authors.forename: Chauying J
authors.initials: CJ
authors.lastname: Jen
authors.forename: Shih-Ying
authors.initials: SY
authors.lastname: Wu
authors.forename: Chen-Peng
authors.initials: CP
authors.lastname: Lo
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Kuo
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D049109:Cell Proliferation; D002470:Cell Survival; D003345:Corticosterone / Q000097:blood; D018891:Dentate Gyrus / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016501:Neurites / Q000378:metabolism / Q000502:physiology*; D055495:Neurogenesis; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D005082:Physical Exertion; D020813:Receptor, trkB / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020813:Receptor, trkB; D003345:Corticosterone