Effect of Short-time Exposure of Local Extremely Low-Frequency Magnetic Fields on Sleepiness in Male Rats

INTRODUCTION: Lack of high-quality sleep causes severe side effects like anxiety and changes in plasma concentration of oxalate. The current study investigated the impact of local extremely low-frequency magnetic fields (ELF-MFs) on inducing sleep (sleepiness) and anxiety in male rats. METHODS: In this experimental study, 40 male rats were divided into four groups (n=10 for each group). The ELF-MF exposure (0, 10, and 18 Hz) was applied with an intensity of 200μT for three days (10 min/d). The sham-treated animal did not receive ELF-MF. Serum levels of oxalic acid (OA) and sleepiness were measured before and after the last exposure to ELF-MF or sham. Anxiety, sleepiness, and OA were measured using the elevated plus maze, open-field test (OFT), and ELISA test. RESULTS: A comparison of oxalate levels before and after exposure to ELF-MF revealed that ELF-MF (10 Hz) decreased the serum level of oxalate (P<0.05). Comparing open/closed arm entry (in an elevated plus maze) between before and after exposure to ELFMF revealed significant differences. Also, frequency, velocity, and distance moved were decreased in the open-field test. CONCLUSION: Results of the present study demonstrated that ELF-MF with short-time exposure may modulate the metabolism of OA and may modulate anxiety-like behavior or kind of induction of sleepiness in male rats. HIGHLIGHTS: Oxalate acid concentration may reduce after short time ELF-MF exposure. Locomotor activity in male rats may decrease after the ELF-MF exposure. Short time ELF-MF exposure may induce sleepiness in male rats that may be used to treat sleep disorders. PLAIN LANGUAGE SUMMARY: It is necessary for a person to have good sleep to feel happy during the day. The usual way to treat the patient’s sleep disorders is drug therapy, but there are some non-pharmacological treatments such as cognitive behavioral therapy and proper diet. In this study we decided to evaluate the effect of ELF-MFs on sleep induction (sleepiness) in male rats by assessing behavioral tests and measuring oxalate acid density. The results showed that the activity of rats and oxalate acid concentration reduced after ELF-MF exposure. This was consistent with results of the plus maze test and the reduction of velocity, frequency and in the open-field test can be attributed to sleepiness. The results of this research showed that ELF-MF with short time exposure may modulate the anxiety-like behavior or kind of induction of sleepiness in male rats. This effect may be used to treat sleep disorders and requires further human studies.