부산대학교 도서관

In rodents, hippocampal neurogenesis and synaptogenesis phenomena are affected by exercise. However, the role of exercise parameters such as intensity, duration, and mode on molecular mechanisms involved in these processes has not been elucidated. In this study, we evaluated the effects of different intensities and modes of running on the expression of genes contributing to neuronal differentiation and synapse formation in the hippocampus of adult male rats. Adult male Wistar rats (n = 24) were randomly divided into control, low-intensity running (LIR), high-intensity running (HIR), and the voluntary wheel running (WR) conditions. Changes in the expression of microRNA-124 (miR-124), microRNA-132 (miR-132), and their respective targets, were analyzed using quantitative RT-PCR and Western blotting techniques. Our results showed that WR compared to treadmill running increased miR-124 and miR-132 expression, while reducing the expression of their respective targets, glucocorticoid receptor (GR), SRY-Box 9 (SOX9), and GTP-activated protein P250 (P250GAP). Differences in expression levels were statistically significant (p s < 0.05), except for the expression of GR in HIR (P = 0.09). Moreover, the expression level of gene coding for the transcription factor cAMP-response element binding protein (CREB) was significantly higher in the WR group compared to the treadmill running groups (P = 0.001). Western blotting techniques indicated that the level of the CREB protein was higher in WR compared to the other groups qualitatively. These findings demonstrated a more dramatic effect for voluntary running on biomarkers that are associated with stimulating neurogenesis and synapse formation in the hippocampus of male rats compared with forced treadmill running. In addition, greater positive effects were observed for lower-intensity treadmill running as compared with high-intensity running. • Voluntary running seems to have more positive effects on biomarkers involved in neural differentiation than forced running. • In forced running interventions, low-intensity running seems to have beneficial effects compared to higher-intensity running. • Voluntary running may increase neuronal activity via activity-dependent genes CREB and miR-132, thus promoting plasticity. • Our results examined miRNAs as targets for elucidating the effects of exercise training on neurogenesis and synaptogenesis. [ABSTRACT FROM AUTHOR]