Early Exposure to Intermediate-Frequency Magnetic Fields Alters Brain Biomarkers without Histopathological Changes in Adult Mice
AbstractRecently we have reported that intermediate-frequency magnetic field (IF-MF) exposure transiently altered the mRNA expression levels of memory function-related genes in the hippocampi of adult male mice. However, the effects of IF-MF exposure during brain development on neurological biomarkers have not yet been clarified. In the present study, we investigated the effect of IF-MF exposure during development on neurological and immunological markers in the mouse hippocampus in 3- and 7-week-old male mice. Pregnant C57BL/6J mice were exposed to IF-MF (21 kHz, 3.8 mT) for one hour per day from organogenesis period day 7 to 17. At adolescence, some IF-MF-exposed mice were further divided into exposure, recovery, and sham-exposure groups. The adolescent-exposure groups were exposed again to IF-MF from postnatal day 27 to 48. The expression of mRNA in the hippocampi was examined using a real-time RT-PCR method, and microglia activation was examined by immunohistochemical analysis. The expression levels of NR1 and NR2B as well as transcription factors (CaMKIV, CREB1), inflammatory mediators (COX2, IL-1 b,TNF-α), and the oxidative stress marker heme-oxygenase (HO)-1 were significantly increased in the IF-MF-exposed mice, compared with the control group, in the 7-week-old mice, but not in the 3-week-old mice. Microglia activation was not different between the control and other groups. This study provides the first evidence that early exposure to IF-MF reversibly affects the NMDA receptor, its related signaling pathways, and inflammatory mediators in the hippocampus of young adult mice; these changes are transient and recover after termination of exposure without histopathological changes. View Full-Text
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Win-Shwe, T.-T.; Ohtani, S.; Ushiyama, A.; Kunugita, N. Early Exposure to Intermediate-Frequency Magnetic Fields Alters Brain Biomarkers without Histopathological Changes in Adult Mice. Int. J. Environ. Res. Public Health 2015, 12, 4406-4421.
Win-Shwe T-T, Ohtani S, Ushiyama A, Kunugita N. Early Exposure to Intermediate-Frequency Magnetic Fields Alters Brain Biomarkers without Histopathological Changes in Adult Mice. International Journal of Environmental Research and Public Health. 2015; 12(4):4406-4421.Chicago/Turabian Style
Win-Shwe, Tin-Tin; Ohtani, Shin; Ushiyama, Akira; Kunugita, Naoki. 2015. "Early Exposure to Intermediate-Frequency Magnetic Fields Alters Brain Biomarkers without Histopathological Changes in Adult Mice." Int. J. Environ. Res. Public Health 12, no. 4: 4406-4421.