Running throughout middle‐age improves memory function, hippocampal neurogenesis, and BDNF levels in female C57BL/6J mice

TLDR

Age‑related memory decline begins in middle age and is associated with reduced hippocampal neurogenesis and neurotrophin levels, while sustained physical activity may preserve BDNF, new cell genesis, and learning. Nine‑month‑old female C57BL/6J mice were given running wheels or no wheel, received BrdU to label newborn cells, and were evaluated with Morris water maze, open field, and rotarod tests at 1 and 6 months of exercise. Long‑term running enhanced spatial memory retention and modestly improved rotarod performance at 15 months, and increased hippocampal neurogenesis and mature BDNF, suggesting that regular exercise during middle age preserves brain function.

Abstract

Age-related memory loss is considered to commence at middle-age and coincides with reduced adult hippocampal neurogenesis and neurotrophin levels. Consistent physical activity at midlife may preserve brain-derived neurotrophic factor (BDNF) levels, new cell genesis, and learning. In the present study, 9-month-old female C57Bl/6J mice were housed with or without a running wheel and injected with bromodeoxyuridine (BrdU) to label newborn cells. Morris water maze learning, open field activity and rotarod behavior were tested 1 and 6 months after exercise onset. Here we show that long-term running improved retention of spatial memory and modestly enhanced rotarod performance at 15 months of age. Both hippocampal neurogenesis and mature BDNF peptide levels were elevated after long-term running. Thus, regular exercise from the onset and during middle-age may maintain brain function.