Comparison of the effect of high intensity interval training and voluntary exercise in motor enriched environment on the expression of irisin and adiponectin proteins in the hippocampal tissue of rats with Alzheimer's disease

Although the beneficial role of exercise in the health of patients with Alzheimer's (AD) has been reported, the mechanism of these effects on neuronal function in these patients is still not well understood. Therefore, the present study was designed to compare the effect of high intensity interval training (HIIT) and exercise in motor enriched environment (RE) on the expression of irisin and adiponectin proteins in the hippocampal tissue of Alzheimer's rats.

In this experimental study, 25 rats were divided into (1) control, (2) sham (Sh), (3) streptozotocin Alzheimer's model (AD) (4) high intensity interval training (HIIT) and (5) Exercises in motor enriched environment (RE). The HIIT group trained for eight weeks, five sessions per week and each session in 90 seconds practice in 9interval with an intensity of 85% of maximum speed, and the RE group were placed in especially motor enriched cages. In order to confirm the Alzheimer's model, thioflavin staining was used. One-way ANOVA with Tukey’ s post-hoc test was used for data analysis (P≤0.05).

The RE exercises significantly increased in irisin levels compared to the Alzheimer's group (P=0.0009), HIIT exercises resulted in no significant change in irisin levels. None of the training methods caused significant changes in adiponectin level (P>0.05).

Activity in an enriched motor environment through the irisin mechanism has more desirable effects in reducing AD symptoms