The Effect of 12 Hz Extremely Low-frequency Electromagnetic Field on Visual Memory of Male Macaque Monkeys

Abstract

Introduction: Today, humans leave in a world surrounded by electromagnetic fields. Numerous studies have been carried out to discover the biological, physiological, and behavioral effects of electromagnetic fields on humans and animals. Given the biological similarities between monkeys and humans, the goal of the present research was to examine Visual Memory (VM), hormonal, genomic, and anatomic changes, and changes of the amygdala function in the male rhesus macaques who exposed to extremely low-frequency magnetic fields (ELF/MF). Materials and methods: Four male Rhesus Macaques (Macaca mulatta) were used. For the behavioral tests the animals were needed to be fasting for 17 hours, and for the behavioral tests such as visual memory, cooperation of the animal was necessary. Using the radiation protocol, two of the monkeys were exposed to 12-Hz electromagnetic fields with a magnitude of 0.7 microtesla (electromagnetic radiation) four hours a day for a month. Before and after the exposure, a visual memory test was conducted using a coated device (visible reward) on a movable stand. Ten mL of blood was obtained from the femoral artery of the monkeys and half of it was used to examine cortisol serum levels using MyBioSource kits (made in the USA). The other half of blood samples were used to extract lymphocytes for assaying expressions of Glucocorticoid Receptor (GR) genes before and after radiation using the PCR method. Anatomic studies of the amygdala were carried out based on pre- and post-radiation Magnetic Resonance Imaging (MRI). Findings: Research results indicated that visual memory in male primates increased significantly at the 12Hz frequency. Hormonal analysis at the 12Hz frequency showed a decrease in cortisol serum levels. However, visual memory and serum cortisol levels did not change considerably in male primates in the control group. There was no considerable amygdala volumetric difference at the 12 Hz frequency. The expression of the GR genes decreased at 12Hz compared to the control group. Conclusion: In short, these results indicated that ELF may have a beneficial value for memory enhancement as indicated by the fact that exposure to the 12 HZ ELF can enhance visual memory. This may be due to a decrease in plasma cortisol, and/or expression of GR genes. Moreover, direct involvement of the amygdala in this regard cannot be recommended.

Effects of Electromagnetic Field Frequency on the Behavior and Mortalities of Living Organisms

“…Studies on the effect of very low-frequency EMFs (7-75 Hz) on monkeys showed no change in their behavior. Sometimes minor differences in activity and response rates were observed, but no sustained effects were achieved (Kazemi et al, 2022). This experience, therefore, proves that electromagnetic radiation has a negative impact on animals.…”

The Effect of Extremely Low-Frequency Magnetic Field on Stroke Patients: A Systematic Review

“…It is reported that ELF-MFs can modulate the activity of the human brain cortex [44]. Meta analysis performed by Barth et al [45], which included nine studies, showed a limited significant positive effect of ELF-MFs on the cognitive abilities of exposed subjects; moreover, studies on rats [46] and monkeys [47] also showed that ELF-MFs improved the cognitive abilities of those animals. The observed improvement in cognitive abilities due to ELF-MF stimulation may result from a facilitation of forming new neurons in the hippocampal area, as demonstrated in studies on rats [46].…”

Unveiling the biological effects of radio-frequency and extremely-low frequency electromagnetic fields on the central nervous system performance

“… 140 Kazemi et al have suggested that exposing Wrhesus macaquesistar monkeys to ELF-EMF with 12 Hz frequency and 0.7 μT magnetic intensity for 4 hours/day for 30 days may improve visual memory and, consequently, enhance general memory, which is sought to be caused by a decrease in GR genes expression and plasma cortisol. 141 Also, in a similar study, Kazemi et al exposed Wrhesus macaquesistar monkeys to 12 Hz EL-EMF and magnetic intensity of 0.7 μT for 4 hours/day for 30 days. 142 Based on the findings, 12 Hz ELF-EMF exposure may increase scores of visual working memory (VWM), which translates to improvement in memory.…”