Effects of extremely low frequency electromagnetic field (50 Hz) on pentylenetetrazol-induced seizures in mice

The electromagnetic fields (EMF) have various behavioral and biological effects on human body. There are growing concerns about the consequences of exposure to EMF. However, some studies have shown beneficial effects of these waves on human. In this paper, we study the effect of acute, sub acute and long-term exposure to 50 Hz, 0.1 mT magnetic fields (MF) on the seizure induction threshold in mice. 64 mice are used and divided into four groups. Eight mice in any group were selected to be exposed to MF for specific duration and the others were used as a control group. The duration of the applied exposures was as follows: (1) 1 day (acute), (2) 3 days (sub acute), (3) 2 weeks (sub acute), (4) 1 month (long term). The mice were exposed 2 h for a day. After exposure, the pentylentetrazol (PTZ) is injected to the mice to induce seizure and the needed dose for the seizure induction threshold is measured. In the acute exposure, the threshold to induce seizure in the exposed and sham-exposed groups was 44.25 and 46.5 mg, respectively, while the difference was not significant (p value = 0.5). In the sub acute exposure (3 days), the mean amount of drug to induce seizure was 47.38 mg in the exposed and 43.88 mg in the sham-exposed groups, however, the difference was not significant (p value = 0.3). The results were 52.38 and 46.75 mg after 2 weeks of exposure which were not significantly different either (p value = 0.2). After 1 month of exposure to MF, the threshold for the induction of seizure was significantly increased (p value < 0.05). The mean dosage to induce seizure in the exposed and control group was 54.3 and 45.75 mg, respectively. However, considering the p value, the difference in the seizure induction threshold between the exposed and sham-exposed groups after acute and sub acute exposure was not significant, analyzing the effects of acute, sub acute and long-term exposures totally indicates that increasing the exposure time increases the seizure induction threshold.