Effect of Eight Weeks of Interval Training on Amyloid Precursor Protein (APP) Gene Expression in Hippocampal Tissue in Methamphetamine-dependent Rats (Crystal)

Methamphetamine (METH) is a stimulant drug that causes memory and learning disorders. The present study aimed to investigate the effect of eight weeks of interval training on APP gene expression in hippocampal tissue and open field test in methamphetamine-dependent rats.

In this experimental research, 32 rats were assigned to four equal groups of saline, primary methamphetamine (METH-1), methamphetamine+training (METH+MIT), and secondary methamphetamine (METH-2). The METH was injected at the dose of 5 mg/kg body weight for 21 days. The exercise program (5 sessions per week) included interval training (4 sets of 4 minutes with moderate intensity and 2 minutes of active rest between sets) on a treadmill. At the end of the injection and training period, the hippocampus tissue of the rats was extracted to evaluate gene expression changes. An open-field behavioral test was also conducted. The data were analyzed using the one-way ANOVA at the significance level of P≥0.05.

Methamphetamine significantly increased APP gene expression in METH-1,2 groups compared to saline (respectively; P≥0.007 and P≥0.005). The total distance and movement speed of rats in METH-1 and 2 groups had a significant decrease compared to saline (respectively, P≥0.004 and P≥0.026). The MIT led to a significant reduction of APP compared to METH-1,2 groups (respectively, P≥0.041 and P≥0.028). Movement speed in the MIT group increased significantly compared to the METH-1 group (P≥0.008).

Methamphetamine reduced cognitive performance (learning and memory), and according to the results, MIT probably improved cognitive performance. Nonetheless, further studies are necessary to reach definitive conclusions.