High-intensity interval training improves cognitive impairment of vascular dementia rats by up-regulating expression of brain-derived neurotrophic factor in the hippocampus.

The present study aims to investigate the effect and its potential mechanism of high-intensity intermittent training (HIIT) on cognitive function in vascular dementia (VD) rats. The VD rats with the cognitive impairment were induced by bilateral common carotid artery occlusion (BCCAO), and the ones in the moderate-intensity continuous training (MICT) group and HIIT group received MICT or HIIT for 5 consecutive weeks, respectively. The swimming speed, endurance, and grip strength of rats were all measured after training. The effect and mechanisms of HIIT on ameliorating the cognitive dysfunction were further evaluated by the Morris water maze test, histomorphological analysis, and Western blot analysis. As a result, no significant difference in motor function between VD rats and sham rats was observed. After 5-week HIIT, the motor function of VD rats was significantly enhanced. The results of the Morris water maze test revealed that HIIT significantly reduced escape latency as well as distance to find the platform compared with the sedentary control group (SED group), indicating the improvement in cognitive function. In addition, the hippocampal tissue damage of VD rats measured by H&E staining was markedly ameliorated after 5-week HIIT. Moreover, brain-derived neurotrophic factor (BDNF) expression level in the cerebral cortex and hippocampus tissue detected by Western blot were significantly up-regulated in HIIT group compared to SED group and MICT group. In conclusion, HIIT can improve BCCAO-induced cognitive impairment via up-regulating BDNF expression in VD rats.