title: Chronic exposure to an extremely low-frequency magnetic field induces depression-like behavior and corticosterone secretion without enhancement of the hypothalamic-pituitary-adrenal axis in mice.
abstract: An extremely low-frequency magnetic field (ELF-MF) is generated by power lines and household electrical devices. Many studies have suggested an association between chronic ELF-MF exposure and anxiety and/or depression. The mechanism of these effects is assumed to be a stress response induced by ELF-MF exposure. However, this mechanism remains controversial. In the present study, we investigated whether chronic ELF-MF exposure (intensity, 1.5 mT; [corrected] total exposure, 200 h) affected emotional behavior and corticosterone synthesis in mice. ELF-MF-treated mice showed a significant increase in total immobility time in a forced swim test and showed latency to enter the light box in a light-dark transition test, compared with sham-treated (control) mice. Corticosterone secretion was significantly high in the ELF-MF-exposed mice; however, no changes were observed in the amount of the adrenocorticotropic hormone and the expression of genes related to stress response. Quantification of the mRNA levels of adrenal corticosteroid synthesis enzymes revealed a significant reduction in Cyp17a1 mRNA in the ELF-MF-exposed mice. Our findings suggest the possibility that high intensity and chronic exposure to ELF-MF induces an increase in corticosterone secretion, along with depression- and/or anxiety-like behavior, without enhancement of the hypothalamic-pituitary-adrenal axis.
authors: Department of Physiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan. kitaoka@basic.med.tokushima-u.ac.jp
authors: Kazuyoshi
authors: K
authors: Kitaoka
authors: Mitsuo
authors: M
authors: Kitamura
authors: Shun
authors: S
authors: Aoi
authors: Noriyuki
authors: N
authors: Shimizu
authors: Kazuo
authors: K
authors: Yoshizaki
mesh_terms: D000311:Adrenal Glands / Q000528:radiation effects*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects; D049628:Body Size / Q000528:radiation effects; D003345:Corticosterone / Q000097:blood / Q000378:metabolism*; D003863:Depression / Q000097:blood / Q000201:enzymology / Q000209:etiology* / Q000378:metabolism; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004644:Emotions / Q000528:radiation effects; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D007030:Hypothalamo-Hypophyseal System / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009638:Norepinephrine / Q000097:blood; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics
chemical_list: D000324:Adrenocorticotropic Hormone; D014446:Tyrosine 3-Monooxygenase; D003345:Corticosterone; D009638:Norepinephrine