Comparison of the effects of Hight intensity interval training and motor environmental richness activity on the expression of leptin and brain-derived neurotrophic factor proteins in the hippocampal tissue of Alzheimer's rats

The effect of exercise training on some cognitive mechanisms in Alzheimer's (AD) patients is not yet well understood. Therefore, the aim of this study was to compare the effect of intense intermittent exercise (HIIT) and motor environmental richness activity (MERA) on the expression of leptin and brain-derived nutritional factor (BDNF) in the hippocampal of rats with Alzheimer disease (AD). In this experimental study, 24 rats with AD were divided into (1) AD control groups, (2) HIIT group and (3) MERA group. The sham group was considered to evaluate the effect of surgery and saline injection and the healthy control group (HC) was considered to evaluate the effect of AD induction. The HIIT group trained for eight weeks, five sessions per week and each session in 9 repetition of 90-second intervals (with 85% of maximum speed), and the MERA training group was placed in special enriched movement cages. One-way analysis of variance with Tukey's post hoc test was used to analyze the data (P≥0.05). The results showed that in AD group, BDNF levels (P=0.001) were lower and leptin levels (P=0.001) were higher than HC group. In the HIIT group, leptin levels (P=0.005) were lower and BDNF levels (P=0.019) were higher than the AD group. There was no significant difference in leptin (P=0.72) and BDNF (P=0.65) between the two training groups. Both HIIT and MERA appear to be effective in improving neurotrophins and hippocampal metabolism, but the effect of intense intermittent exercise is more favorable due to exercise-induced adaptation.