| Zdroj: |
FASEB Journal; Jul2008, Vol. 22 Issue 7, p2253-2262, 10p, 1 Black and White Photograph, 2 Diagrams, 1 Chart, 2 Graphs |
| Abstrakt: |
Adult hippocampal neurogenesis is influenced by a variety of stimuli, including exercise, but the mechanisms by which running affects neurogenesis are not yet fully understood. Because β-endorphin, which is released in response to exercise, increases cell proliferation in vitro, we hypothesized that it could exert a similar effect in vivo and mediate the stimulatory effects of running on neurogenesis. We thus analyzed the effects of voluntary wheel-running on adult neurogenesis (proliferation, differentiation, survival/death) in wild-type and β-endorphin-deficient mice. In wild-type mice, exercise promoted cell proliferation evaluated by sacrificing animals 24 h after the last 5-bromo-2'-deoxyuridine (BrdU) pulse and by using endogenous cell cycle markers (Ki67 and pHs). This was accompanied by an increased survival of 4-wk-old BrdU-labeled cells, leading to a net increase of neurogenesis. β-Endorphin deficiency had no effect in sedentary mice, but it completely blocked the runninginduced increase in cell proliferation; this blockade was accompanied by an increased survival of 4-wk-old cells and a decreased cell death. Altogether, adult neurogenesis was increased in response to exercise in knockout mice. We conclude that β-endorphin released during running is a key factor for exercise-induced cell proliferation and that a homeostatic balance may regulate the final number of new neurons. Koehl, M., Meerlo, P., Gonzales, D., Rontal, A., Turek, F. W., Abrous, D. N. Exercise-induced promotion of hippocampal cell proliferation requires β-endorphin. [ABSTRACT FROM AUTHOR] |
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