Maternal exercise enhances hippocampal plasticity and resilience against stress-induced depressive behaviors in adult offspring

Maternal physical activity during pregnancy has been shown to confer benefits on the brain functions of offspring. This study investigated the positive effects of maternal exercise during pregnancy on enhancing hippocampal synaptic plasticity and resilience to stress-induced depressive behavior in adult murine offspring. Using a mouse model with mother mice engaged in voluntary wheel running during pregnancy, we assessed changes in long-term potentiation (LTP) in the hippocampal dentate gyrus, synaptic protein expression, and behavioral responses to chronic stress in adult male and female offspring from exercised dams compared with those from sedentary dams. We found that maternal exercise enhanced LTP in offspring of both sexes. Western blot analysis of hippocampal synaptoneurosome extractions revealed significant main effects of maternal exercise on increasing the expression of brain-derived neurotrophic factor (BDNF), PSD-95, synaptophysin, and phosphorylation of N-methyl-D-aspartate receptor subunit GluN2A and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluA1. Maternal exercise significantly increased synaptophysin levels in both male and female offspring, with sex-specific effects on increasing PSD-95 levels in male offspring and increased p-GluN2A levels in female offspring from exercised dams. Golgi staining revealed a significant increase in hippocampal dendritic spine density in female offspring only. Maternal exercise-induced improvements in hippocampal synaptic plasticity were associated with reduced depression-like behaviors in both male and female offspring exposed to chronic unpredictable stress. Additionally, male offspring displayed reduced anxiety-like behavior, while female offspring showed no significant anxiolytic changes. These findings elucidate the sex-specific effects of maternal exercise on enhancing hippocampal synaptic plasticity, which may contribute to increased resilience against stress-induced depressive behaviors in adult offspring.