Physical exercise can improve various brain function, including memory and learning, emotion and cognitive/executive functions. It is considered that these multiple effects of exercise are due to interaction of neural activation of multiple brain regions stimulated by exercise. Thus, it is possible that physical exercise can form exercise-specific functional brain network, which is defined by co-activation of multiple brain regions. However, the functional brain network underlying the beneficial effects of exercise remain unclear. Previous studies have suggested that the beneficial effects of exercise on brain functions are different depending on intensity of the exercise. Thus, it is possible that the functional brain network recruited by exercise may depend on intensity of the exercise. In the present study, we tried to identify the functional brain network recruited by acute treadmill running at different intensities (30 min; high speed, 25 m/min; low speed, 15 m/min; control, only sitting on the treadmill) in male Wistar rats, using c-Fos immunohistochemistry and correlation analysis. We selected 25 brain regions as ROI, including cortex, limbic system, hypothalamus, and brainstem, which are regions associated with mental or motor functions. We mapped functional brain network recruited by each physical exercise, using correlation analysis to the inter-regional c-Fos expression data obtained after each exercise condition. Acute treadmill running increased c-Fos expression of motor cortex, sensory cortex, amygdala and hippocampus, regardless of exercise intensity. On other hand, high speed group showed significantly more c-Fos-positive cells in medial prefrontal cortex, the hypothalamic paraventricular nucleus, and the locus ceruleus nucleus, compared to control group. Low speed group showed significantly more c-Fos-positive cells in the dorsal raphe nucleus and cingulate cortex, compared to control group. These results suggests that the effects of exercise on brain functions are different depending on intensity of the exercise. Furthermore, the functional brain network of low speed group had more connection expressing inter-regional negative correlation than the functional brain network of control group, whereas the functional brain network of high speed had no connection expressing inter-regional negative correlation. These results suggest that acute physical exercise at different intensities could form intensity-specific functional brain networks.

研究助成：Research funds : KAKENHI 16K13017