Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment

Abstract

Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment Kumari K, Koivisto H, Viluksela M, Paldanius KMA, Marttinen M, Hiltunen M, Naarala J, Tanila H, Juutilainen J. Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment. PLoS One. 2017 Dec 4;12(12):e0188880. doi: 10.1371/journal.pone.0188880. Abstract Human exposure to intermediate frequency magnetic fields (MF) is increasing due to applications like electronic article surveillance systems and induction heating cooking hobs. However, limited data is available on their possible health effects. The present study assessed behavioral and histopathological consequences of exposing mice to 7.5 kHz MF at 12 or 120 μT for 5 weeks. No effects were observed on body weight, spontaneous activity, motor coordination, level of anxiety or aggression. In the Morris swim task, mice in the 120 μT group showed less steep learning curve than the other groups, but did not differ from controls in their search bias in the probe test. The passive avoidance task indicated a clear impairment of memory over 48 h in the 120 μT group. No effects on astroglial activation or neurogenesis were observed in the hippocampus. The mRNA expression of brain-derived neurotrophic factor did not change but expression of the proinflammatory cytokine tumor necrosis factor alpha mRNA was significantly increased in the 120 μT group. These findings suggest that 7.5 kHz MF exposure may lead to mild learning and memory impairment, possibly through an inflammatory reaction in the hippocampus. Open Access Paper: ncbi.nlm.nih.gov

AI evidence extraction

Main findings

Mice were exposed to 7.5 kHz magnetic fields at 12 or 120 μT for 5 weeks. No effects were observed on body weight, spontaneous activity, motor coordination, anxiety, or aggression. In the 120 μT group, the Morris swim task showed a less steep learning curve (with no difference from controls in probe-test search bias) and passive avoidance indicated impaired memory over 48 h; hippocampal TNF-α mRNA was increased while astroglial activation, neurogenesis, and BDNF mRNA were unchanged.

Outcomes measured

• Body weight
• Spontaneous activity
• Motor coordination
• Anxiety
• Aggression
• Learning and memory (Morris swim task)
• Memory (passive avoidance over 48 h)
• Astroglial activation in hippocampus
• Neurogenesis in hippocampus
• mRNA expression of brain-derived neurotrophic factor (BDNF)
• mRNA expression of tumor necrosis factor alpha (TNF-α)

Suggested hubs

• intermediate-frequency (0.95)
  Animal study of 7.5 kHz intermediate-frequency magnetic field exposure.

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