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Lai H. Neurological effects of static and extremely-low frequency electromagnetic fields. Electromagn Biol Med 2022; 41:201-221. [DOI: 10.1080/15368378.2022.2064489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Henry Lai
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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Zuo H, Liu X, Li Y, Wang D, Hao Y, Yu C, Xu X, Peng R, Song T. The mitochondria/caspase-dependent apoptotic pathway plays a role in the positive effects of a power frequency electromagnetic field on Alzheimer's disease neuronal model. J Chem Neuroanat 2020; 109:101857. [PMID: 32918997 DOI: 10.1016/j.jchemneu.2020.101857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/20/2020] [Accepted: 09/06/2020] [Indexed: 11/16/2022]
Abstract
In this study, rat pheochromocytoma (PC12) cells were induced into an Alzheimer's Disease (AD) neuronal model using nerve growth factor (NGF; 50 ng/mL) and Amyloid β25-35 (20 μmol/L). Changes in the morphological structure, cell viability, apoptosis rate, and expression of apoptosis-related protein induced by exposure to a power frequency electromagnetic field (PF-MF; 50 Hz, 100 μT, 24 h) were detected respectively by light and electron microscopy, the MTT assay, immunohistochemistry, flow cytometry and enzyme-linked immunosorbent assays. The results showed that 3-12 h after PF-MF exposure, the pathological injury was improved partly; metabolic activity was promoted and cell apoptosis was inhibited in the AD neuronal model. In addition, PF-MF exposure significantly inhibited the expression of Caspase8, Caspase3, and CytC, but increased the Bcl-2/Bax ratio of the AD neuronal model. Meanwhile, PF-MF seemed to have no effect on the expression of Fas and TNFR1. This study indicated that the mitochondria/caspase-dependent apoptotic pathway plays an important role in the positive effects of PF-MF on an AD neuronal model. The results suggested that PF-MF exposure might have potential therapeutic value for AD, and the underling molecular mechanisms still need further studies.
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Affiliation(s)
- Hongyan Zuo
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China.
| | - Xiao Liu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China; Department ofPathology, Hainan Hospital of PLA General Hospital, Sanya 572013, China
| | - Yang Li
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China; Anhui Medical University, Hefei 230032, China
| | - Dewen Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Yanhui Hao
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Chao Yu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Xinping Xu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Ruiyun Peng
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Tao Song
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
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Yavaş MC, Akpolat V, Deveci E, Bilgin HM, Kaplan I, Seker U, Yildiz İ, Alkis E, Celik MS, Akdağ MZ. Determining the effect of an electromagnetic field generated by a high voltage power line on rat spermatogonia cells. DICLE MEDICAL JOURNAL 2018. [DOI: 10.5798/dicletip.497923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Xu Y, Gu X, Di G. Duration-dependent effect of exposure to static electric field on learning and memory ability in mice. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:23864-23874. [PMID: 29881961 DOI: 10.1007/s11356-018-2458-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/30/2018] [Indexed: 06/08/2023]
Abstract
With the rapid development of ultra-high-voltage direct-current (UHVDC) transmission, the strength of environmental static electric field (SEF) around UHVDC transmission lines increased substantially, which has aroused widely public attention on the potential health effects of SEF. In this study, the effect of SEF exposure on learning and memory ability was investigated. Institute of Cancer Research mice were exposed to 56.3 kV/m SEF for a short term (7 days) or long term (49 days). Behaviors in the Morris water maze (MWM) test, hippocampal neurotransmitter contents, and oxidative stress indicators were examined. Results showed that short-term SEF exposure significantly prolonged escape latency and decreased the number of platform-site crossovers, as well as decreased the time spent in the target quadrant in the MWM test. Meanwhile, serotonin level and the ratio of glutamate level to γ-aminobutyric acid level changed significantly. Besides, malondialdehyde content and glutathione peroxidase activity increased significantly, while superoxide dismutase activity decreased significantly. After long-term SEF exposure, all indices above showed no significant differences between the SEF and sham exposure groups. These data indicated that short-term exposure to 56.3 kV/m SEF could cause abnormal neurotransmitter levels and oxidative stress in the hippocampus, which led to the decline in learning and memory ability. Under the condition of long-term exposure, the SEF-induced disturbances in neurotransmitter contents and redox balance were offset by the compensatory responses of mice, and thus, the learning and memory ability returned to normal level. The temporary and reversible decline in learning and memory ability was only a common biological effect of SEF rather than a health hazard.
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Affiliation(s)
- Yaqian Xu
- Department of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Xiaoyu Gu
- Department of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Guoqing Di
- Department of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China.
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Zuo H, Liu X, Wang D, Li Y, Xu X, Peng R, Song T. RKIP-Mediated NF-κB Signaling is involved in ELF-MF-mediated improvement in AD rat. Int J Med Sci 2018; 15:1658-1666. [PMID: 30588189 PMCID: PMC6299414 DOI: 10.7150/ijms.28411] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/12/2018] [Indexed: 12/24/2022] Open
Abstract
In a previous study, we reported the positive effects of extremely low frequency electromagnetic field (ELF-MF) exposure on Alzheimer's disease (AD) rats; however, the underlying mechanism remains unclear. In addition, we found that Raf-1 kinase inhibitor protein (RKIP) was downregulated by microwave exposure in the rat hippocampus. Our hypothesis was that RKIP-mediated NF-κB pathway signaling is involved in the effect of ELF-MF on the AD rat. In this study, D-galactose intraperitoneal (50 mg/kg/d for 42 d) and Aβ25-35 hippocampal (5 μL/unilateral, bilateral, single-dose) injection were implemented to establish an AD rat model. Animals were exposed to 50 Hz and 400 µT ELF-MF for 60 continuous days. The spatial memory ability of the rat was then tested using the Morris water maze. Protein expression and interaction were detected by western blotting and co-immunoprecipitation for RKIP-mediated NF-κB pathway factors. The results showed that ELF-MF exposure partially improved the cognitive disorder, upregulated the levels of RKIP, TAK1, and the RKIP/TAK1 interaction, but downregulated p-IKK levels in AD rats. These results indicated that RKIP-mediated NF-κB pathway signaling plays an important role in the ELF-MF exposure-mediated improvements in the AD rat. Our study suggested that ELF-MF exposure might have a potential therapeutic value for AD. Further in depth studies are required in the future.
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Affiliation(s)
- Hongyan Zuo
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiao Liu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Dewen Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yang Li
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xinping Xu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Ruiyun Peng
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Tao Song
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
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Akbarnejad Z, Esmaeilpour K, Shabani M, Asadi-Shekaari M, Saeedi Goraghani M, Ahmadi-Zeidabadi M. Spatial memory recovery in Alzheimer's rat model by electromagnetic field exposure. Int J Neurosci 2017; 128:691-696. [PMID: 29185809 DOI: 10.1080/00207454.2017.1411353] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Although studies have shown a potential association between extremely low frequency electromagnetic fields (ELF-EMFs) exposure and Alzheimer's disease (AD), few studies have been conducted to investigate the effects of weak magnetic fields on brain functions such as cognitive functions in animal models. Therefore, this study aimed to investigate the effect of ELF-EMF exposure (50 Hz, 10 mT) on spatial learning and memory changes in AD rats. METHODS Amyloid-β (Aβ) 1-42 was injected into lateral ventricle to establish an AD rat model. The rats were divided into six groups: Group I (control); Group II (surgical sham); Group III (AD) Alzheimer's rat model; Group IV (MF) rats exposed to ELF-MF for 14 consecutive days; Group V (Aβ injection+M) rats exposed to magnetic field for 14 consecutive days from day 0 to 14 days after the Aβ peptide injection; Group VI (AD+M) rats exposed to magnetic field for 14 consecutive days after 2 weeks of Aβ peptide injection from 14th to 28th day . Morris water maze investigations were performed. RESULTS AD rats showed a significant impairment in learning and memory compared to control rats. The results showed that ELF-MF improved the learning and memory impairments in Aβ injection+M and AD+M groups. CONCLUSION Our results showed that application of ELF-MF not only has improving effect on different cognitive disorder signs of AD animals, but also disrupts the processes of AD rat model formation.
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Affiliation(s)
- Zeinab Akbarnejad
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran.,b ENT and Head & Neck Research Center , Iran University of Medical Sciences (IUMS) , Tehran , Iran
| | - Khadijeh Esmaeilpour
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Mohammad Shabani
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Majid Asadi-Shekaari
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Monavvar Saeedi Goraghani
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Meysam Ahmadi-Zeidabadi
- a Neuroscience Research Center , Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
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Su L, Yimaer A, Wei X, Xu Z, Chen G. The effects of 50 Hz magnetic field exposure on DNA damage and cellular functions in various neurogenic cells. JOURNAL OF RADIATION RESEARCH 2017; 58:474-486. [PMID: 28369556 PMCID: PMC5570089 DOI: 10.1093/jrr/rrx012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Indexed: 05/15/2023]
Abstract
Epidemiological studies have indicated a possible association between extremely low-frequency magnetic field (ELF-MF) exposure and the risk of nervous system diseases. However, laboratory studies have not provided consistent results for clarifying this association, despite many years of studies. In this study, we have systematically investigated the effects of 50 Hz MF exposure on DNA damage and cellular functions in both neurogenic tumor cell lines (U251, A172, SH-SY5Y) and primary cultured neurogenic cells from rats (astrocytes, microglia, cortical neurons). The results showed that exposure to a 50 Hz MF at 2.0 mT for up to 24 h did not influence γH2AX foci formation (an early marker of DNA double-strand breaks) in any of six different neurogenic cells. Exposure to a 50 Hz MF did not affect cell cycle progression, cell proliferation or cell viability in neurogenic tumor U251, A172 or SH-SY5Y cells. Furthermore, the MF exposure for 24 h did not significantly affect the secretion of cytokines (TNF-α, IL-6 or IL-1β) in astrocytes or microglia, or the phagocytic activity of microglia. In addition, MF exposure for 1 h per day did not significantly influence expression levels of microtubule-associated protein tau, microtubule-associated protein 2, postsynaptic density 95 or gephyrin in cortical neurons, indicating an absence of effects of MF exposure on the development of cortical neurons. In conclusion, our data suggest that exposure to a 50 Hz MF at 2.0 mT did not elicit DNA damage effects or abnormal cellular functions in the neurogenic cells studied.
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Affiliation(s)
- Liling Su
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Department of Clinical Medicine, Jiangxi Medical College, 399 Zhimi Road, Shangrao 331000, China
| | - Aziguli Yimaer
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Xiaoxia Wei
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Zhengping Xu
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Institute of Environmental Health, Zhejiang University School of Public Health, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Guangdi Chen
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Institute of Environmental Health, Zhejiang University School of Public Health, 866 Yuhangtang Road, Hangzhou 310058, China
- Corresponding author. Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China. Tel: +86-571-88208169; Fax: +86-571-88208163;
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Liu X, Zuo H, Wang D, Peng R, Song T, Wang S, Xu X, Gao Y, Li Y, Wang S, Wang L, Zhao L. Improvement of spatial memory disorder and hippocampal damage by exposure to electromagnetic fields in an Alzheimer's disease rat model. PLoS One 2015; 10:e0126963. [PMID: 25978363 PMCID: PMC4433192 DOI: 10.1371/journal.pone.0126963] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 04/09/2015] [Indexed: 01/05/2023] Open
Abstract
Although some epidemiological investigations showed a potential association between long-term exposure of extremely low frequency electromagnetic fields (ELF-EMF) and Alzheimer’s disease (AD), no reasonable mechanism can explain this association, and the related animal experiments are rare. In this study, ELF-EMF exposure (50Hz 400µT 60d) combined with D-galactose intraperitoneal (50mg/kg, q.d., 42d) and Aβ25–35 hippocampal (5μl/unilateral, bilateral, single-dose) injection was implemented to establish a complex rat model. Then the effects of ELF-EMF exposure on AD development was studied by using the Morris water maze, pathological analysis, and comparative proteomics. The results showed that ELF-EMF exposure delayed the weight gain of rats, and partially improved cognitive and clinicopathologic symptoms of AD rats. The differential proteomic analysis results suggest that synaptic transmission, oxidative stress, protein degradation, energy metabolism, Tau aggregation, and inflammation involved in the effects mentioned above. Therefore, our findings indicate that certain conditions of ELF-EMF exposure could delay the development of AD in rats.
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Affiliation(s)
- Xiao Liu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Hongyan Zuo
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
- * E-mail: (HZ); (DW)
| | - Dewen Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
- * E-mail: (HZ); (DW)
| | - Ruiyun Peng
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Tao Song
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, 6 North Second Street, Zhongguancun, Beijing, China
| | - Shuiming Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Xinping Xu
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Yabing Gao
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Yang Li
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Shaoxia Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Lifeng Wang
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
| | - Li Zhao
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing, China
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Todorović D, Prolić Z, Petković B, Kalauzi A. Effects of two different waveforms of ELF MF on bioelectrical activity of antennal lobe neurons of Morimus funereus (Insecta, Coleoptera). Int J Radiat Biol 2015; 91:435-42. [PMID: 25585816 DOI: 10.3109/09553002.2015.1004467] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE External magnetic fields (MF) interact with organisms at all levels, including the nervous system. Bioelectrical activity of antennal lobe neurons of adult Morimus funereus was analyzed under the influence of extremely low frequency MF (ELF MF, 50 Hz, 2 mT) of different characteristics (exposure duration and waveform). MATERIAL AND METHODS Neuronal activity (background/neuronal population and those nearest to the recording electrode) in adult longhorn beetles was registered through several phases of exposure to the sine wave and square wave MF for 5, 10 and 15 min. RESULTS The sine wave MF, regardless of the exposure duration, did not change the reversibility factor of antennal lobe neuronal activity in adult M. funereus. In contrast, reversibility factors of the nearest neurons were significantly changed after the exposure to square wave MF for 10 and 15 min. CONCLUSION M. funereus individuals are sensitive to both sine wave and square wave ELF MF (50 Hz, 2 mT) of different duration, whereby their reactions depend on the characteristics of the applied MF and specificity of each individual.
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Affiliation(s)
- Dajana Todorović
- Institute for Biological Research, University of Belgrade , Belgrade , Serbia
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Lee W, Yang KL. Using medaka embryos as a model system to study biological effects of the electromagnetic fields on development and behavior. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2014; 108:187-194. [PMID: 25084399 DOI: 10.1016/j.ecoenv.2014.06.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 06/27/2014] [Accepted: 06/28/2014] [Indexed: 06/03/2023]
Abstract
The electromagnetic fields (EMFs) of anthropogenic origin are ubiquitous in our environments. The health hazard of extremely low frequency and radiofrequency EMFs has been investigated for decades, but evidence remains inconclusive, and animal studies are urgently needed to resolve the controversies regarding developmental toxicity of EMFs. Furthermore, as undersea cables and technological devices are increasingly used, the lack of information regarding the health risk of EMFs to aquatic organisms needs to be addressed. Medaka embryos (Oryzias latipes) have been a useful tool to study developmental toxicity in vivo due to their optical transparency. Here we explored the feasibility of using medaka embryos as a model system to study biological effects of EMFs on development. We also used a white preference test to investigate behavioral consequences of the EMF developmental toxicity. Newly fertilized embryos were randomly assigned to four groups that were exposed to an EMF with 3.2kHz at the intensity of 0.12, 15, 25, or 60µT. The group exposed to the background 0.12µT served as the control. The embryos were exposed continually until hatch. They were observed daily, and the images were recorded for analysis of several developmental endpoints. Four days after hatching, the hatchlings were tested with the white preference test for their anxiety-like behavior. The results showed that embryos exposed to all three levels of the EMF developed significantly faster. The endpoints affected included the number of somites, eye width and length, eye pigmentation density, midbrain width, head growth, and the day to hatch. In addition, the group exposed to the EMF at 60µT exhibited significantly higher levels of anxiety-like behavior than the other groups did. In conclusion, the EMF tested in this study accelerated embryonic development and heightened anxiety-like behavior. Our results also demonstrate that the medaka embryo is a sensitive and cost-efficient in vivo model system to study developmental toxicity of EMFs.
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Affiliation(s)
- Wenjau Lee
- Department of Bioscience Technology, Chang Jung Christian University, No. 1, Changda Rd., Gueiren District, Tainan City, Taiwan.
| | - Kun-Lin Yang
- Department of Bioscience Technology, Chang Jung Christian University, No. 1, Changda Rd., Gueiren District, Tainan City, Taiwan
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Xiong J, He C, Li C, Tan G, Li J, Yu Z, Hu Z, Chen F. Changes of dendritic spine density and morphology in the superficial layers of the medial entorhinal cortex induced by extremely low-frequency magnetic field exposure. PLoS One 2013; 8:e83561. [PMID: 24376717 PMCID: PMC3869808 DOI: 10.1371/journal.pone.0083561] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 11/09/2013] [Indexed: 01/20/2023] Open
Abstract
In the present study, we investigated the effects of chronic exposure (14 and 28 days) to a 0.5 mT 50 Hz extremely low-frequency magnetic field (ELM) on the dendritic spine density and shape in the superficial layers of the medial entorhinal cortex (MEC). We performed Golgi staining to reveal the dendritic spines of the principal neurons in rats. The results showed that ELM exposure induced a decrease in the spine density in the dendrites of stellate neurons and the basal dendrites of pyramidal neurons at both 14 days and 28 days, which was largely due to the loss of the thin and branched spines. The alteration in the density of mushroom and stubby spines post ELM exposure was cell-type specific. For the stellate neurons, ELM exposure slightly increased the density of stubby spines at 28 days, while it did not affect the density of mushroom spines at the same time. In the basal dendrites of pyramidal neurons, we observed a significant decrease in the mushroom spine density only at the later time point post ELM exposure, while the stubby spine density was reduced at 14 days and partially restored at 28 days post ELM exposure. ELM exposure-induced reduction in the spine density in the apical dendrites of pyramidal neurons was only observed at 28 days, reflecting the distinct vulnerability of spines in the apical and basal dendrites. Considering the changes in spine number and shape are involved in synaptic plasticity and the MEC is a part of neural network that is closely related to learning and memory, these findings may be helpful for explaining the ELM exposure-induced impairment in cognitive functions.
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Affiliation(s)
- Jiaxiang Xiong
- Department of Physiology, Third Military Medical University, Chongqing, PR China
| | - Chao He
- Department of Physiology, Third Military Medical University, Chongqing, PR China
| | - Chao Li
- Department of Physiology, Third Military Medical University, Chongqing, PR China
| | - Gang Tan
- Department of Physiology, Third Military Medical University, Chongqing, PR China
| | - Jingcheng Li
- Department of Physiology, Third Military Medical University, Chongqing, PR China
| | - Zhengping Yu
- Department of Occupational Health, Third Military Medical University, Chongqing, PR China
| | - Zhian Hu
- Department of Physiology, Third Military Medical University, Chongqing, PR China
- * E-mail: (ZH); (FC)
| | - Fang Chen
- Department of Physiology, Third Military Medical University, Chongqing, PR China
- * E-mail: (ZH); (FC)
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