title: Cessation of voluntary wheel running increases anxiety-like behavior and impairs adult hippocampal neurogenesis in mice.
abstract: While increasing evidence demonstrates that physical exercise promotes brain health, little is known on how the reduction of physical activity affects brain function. We investigated whether the cessation of wheel running alters anxiety-like and depression-like behaviors and its impact on adult hippocampal neurogenesis in mice. Male C57BL/6 mice (4 weeks old) were assigned to one of the following groups, and housed until 21 weeks old; (1) no exercise control (noEx), housed in a standard cage; (2) exercise (Ex), housed in a running wheel cage; and (3) exercise-no exercise (Ex-noEx), housed in a running wheel cage for 8 weeks and subsequently in a standard cage. Behavioral evaluations suggested that Ex-noEx mice were more anxious compared to noEx control mice, but no differences were found in depression-like behavior. The number of BrdU-labeled surviving cells in the dentate gyrus was significantly higher in Ex but not in Ex-noEx compared with noEx, indicating that the facilitative effects of exercise on cell survival are reversible. Surprisingly, the ratio of differentiation of BrdU-positive cells to doublecortin-positive immature neurons was significantly lower in Ex-noEx compared to the other groups, suggesting that the cessation of wheel running impairs an important component of hippocampal neurogenesis in mice. These results indicate that hippocampal adaptation to physical inactivity is not simply a return to the conditions present in sedentary mice. As the impaired neurogenesis is predicted to increase a vulnerability to stress-induced mood disorders, the reduction of physical activity may contribute to a greater risk of these disorders.
authors: Department of Functional and Systems Neurobiology, Cajal Institute, CSIC, Doctor Arce 37, Madrid 28002, Spain. t-nishijima@tmu.ac.jp
authors: Takeshi
authors: T
authors: Nishijima
authors: María
authors: M
authors: Llorens-Martín
authors: Gonzalo Sanchez
authors: GS
authors: Tejeda
authors: Koshiro
authors: K
authors: Inoue
authors: Yuhei
authors: Y
authors: Yamamura
authors: Hideaki
authors: H
authors: Soya
authors: José Luis
authors: JL
authors: Trejo
authors: Ignacio
authors: I
authors: Torres-Alemán
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D000963:Antimetabolites; D001007:Anxiety / Q000523:psychology*; D001973:Bromodeoxyuridine; D003863:Depression / Q000523:psychology; D000089622:Doublecortin Domain Proteins; D004435:Eating / Q000502:physiology; D006624:Hippocampus / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009043:Motor Activity / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012420:Running / Q000523:psychology*; D013550:Swimming / Q000523:psychology; D015430:Weight Gain / Q000502:physiology
chemical_list: D000963:Antimetabolites; D000089622:Doublecortin Domain Proteins; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D001973:Bromodeoxyuridine