Efeito do campo magnético de baixa frequência na atividade elétrica cortical de ratos após indução de status epilepticus

Abstract

Today's society constantly uses numerous electrical resources in their daily lives. When the electric charge is put in motion, a magnetic field is generated around the current, when it comes to common electrical wiring the corresponding Electromagnetic Field (EMF) has an extremely low frequency of up to 60 Hz. The literature presents numerous studies dedicated to discovering the influences of exposure to EMF in healthy individuals or in the face of some disorder. However, there are contradictions between the real effects of this exposure, there is no consensus as to the cause, damage to health, possibilities in the treatment of diseases or if it does not cause any influence to organisms. Data linking EMF exposure up to 60 Hz on brain electrical activity are scarce. Epilepsy is the most common neurological disease in the world, and cortical electrical dysfunction makes the epileptic individual sensitive to seizures in several aspects, including the environment. In this way, would the epilepsy patient exposed to EMF be more likely to trigger changes in their cortical electrical dynamics? If so, do such changes cause harm or benefit to the patient? In the present work, we sought to verify the effects of exposure to Magnetic Field (MF) at 60 Hz on the parameters of cortical electrical activity before and after an animal model of status epilepticus in adult male rats. The electrocorticogram (ECoG) was used to record the electrical brain activity of the animals. The ECoG was analyzed by mathematical methods: Spectral Density (SD) and detrended fluctuation analysis (DFA). Eighteen 90-day-old Wistar rats were recorded before and after pilocarpine induction of status epilepticus. After the first record, the animals were divided into two groups (G1 before and G2 before), then one group received only the drug that induces status epilepticus (SE) (G1 after) and the other group received the drug that induces SE and underwent MF (G2 after). The second record was obtained 24 hours after drug administration that induces SE and compared to that obtained before status epilepticus induction. The DFA of the ECoG segment showed no significant difference in any of the groups. SD showed a difference between G1 before and G1 after only in the delta wave. While the DFA of alpha, delta and theta waves showed significant differences between G1 before and G1 after. This study suggests that 24-hour exposure to MF with an intensity of 1 mT and a frequency of 60 Hz was able to attenuate the effects of status epilepticus on brain electrical activity.