Summary: | Aerobic exercise has positive effects on the brain and is associated with improved cognition. One mechanism through which exercise can promote brain health is by increasing adult hippocampal neurogenesis, a phenomenon that produces new function brain cells after the developmental period and throughout life. Meta-analyses of exercise interventions have shown a sex-difference in the efficacy of exercise on cognition in older adults. This current study sought to determine whether there are sex-differences in the efficacy of exercise for promoting neurogenesis and improving cognition in healthy, adult mice. Adult male and female mice were given access to a running wheel (or a disassembled wheel) for 28 days and on day 22 were given 6 days in the Morris water maze, for spatial learning, memory and reversal training. Mice were then sacrificed and examined for neurogenesis in the dentate gyrus using the endogenous protein doublecortin (DCX), a marker for immature neurons. Mice that ran for 28 days showed increased hippocampal neurogenesis, regardless of sex. All mice, irrespective of exercise intervention or sex, showed learned the reference memory version of the Morris water maze. There was a positive correlation between time spent in the platform zone and doublecortin-expressing neurons in the dorsal dentate gyrus in males, but not females. Future studies should continue to address sex-differences in the effects of exercise on neurogenesis and cognition by using more specific and challenging cognitive tests for young, healthy rodents, or using animals with impaired or naturally decreased levels of neurogenesis. === Medicine, Faculty of === Graduate
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