The Effect of Time-Dependence of 10 Hz Electromagnetic Field on Spatial Learning and Memory in Rats

In everyday life, electrical devices are the primary sources of extremely low-frequency electromagnetic fields (ELF-EMF), and the human body may be a great conductor of these fields. We chose alpha band power, especially at 10 Hz frequency, due to its prior beneficial role in memory. The purpose was to clarify whether there is a relationship between ELF-EMF exposure and cognitive deficits in rats, clinical signs, behavioral analysis, and the impact of ELF-EMF during different times of exposure on neuroplasticity via the expression of BDNF.

Forty adult male rats were selected randomly. The rats were exposed to ELF-EMF (10 Hz, 4 mT) for 7 days and 30 days, one hour daily. The expression of BDNF proteins in the hippocampus was evaluated after sacrificing animals to assess learning and memory function. The body weight of rats in the long-term exposed group differed significantly (P < 0.05). The level of BDNF mRNA in the hippocampus was found by the RT-PCR method.

Our findings indicate that exposure to ELF-EMF affects spatial learning and memory and can improve memory, especially with long-term exposure. In addition, we discovered a significant difference in the long-term exposed group (P < 0.05), where radiation for 30 days resulted in a substantial rise in BDNF levels.

After prolonged exposure, male rats spent more time and traveled a greater percentage of their distance in the target quadrant, demonstrating that long-term exposure improves spatial memory and that 10 Hz might be safe.