Effects of electromagnetic fields on neuronal ion channels: a systematic review

Editor — Mon, 10 May 2021 13:31:24 +0000

Bertagna F, Lewis R, Silva SRP, McFadden J, Jeevaratnam K. Effects of electromagnetic fields on neuronal ion channels: a systematic review. Ann N Y Acad Sci. 2021 May 4. doi: 10.1111/nyas.14597. Epub ahead of print. PMID: 33945157.

Abstract

Many aspects of chemistry and biology are mediated by electromagnetic field (EMF) interactions. The central nervous system (CNS) is particularly sensitive to EMF stimuli. Studies have explored the direct effect of different EMFs on the electrical properties of neurons in the last two decades, particularly focusing on the role of voltage-gated ion channels (VGCs). This work aims to systematically review published evidence in the last two decades detailing the effects of EMFs on neuronal ion channels as per the PRISM guidelines. Following a predetermined exclusion and inclusion criteria, 22 papers were included after searches on three online databases. Changes in calcium homeostasis, attributable to the voltage-gated calcium channels, were found to be the most commonly reported result of EMF exposure. EMF effects on the neuronal landscape appear to be diverse and greatly dependent on parameters, such as the field’s frequency, exposure time, and intrinsic properties of the irradiated tissue, such as the expression of VGCs. Here, we systematically clarify how neuronal ion channels are particularly affected and differentially modulated by EMFs at multiple levels, such as gating dynamics, ion conductance, concentration in the membrane, and gene and protein expression. Ion channels represent a major transducer for EMF-related effects on the CNS.

https://pubmed.ncbi.nlm.nih.gov/33945157/

Extract

Limitations of this study

This study investigates a complex field, with sometimes conflicting results. The many variables that influence the impact of EMF exposure on neural tissue, such as the physiological state of the cell, its developmental stage, and the various physical characteristics of the many fields involved, complicate the reproducibility and often impede a consistent comparison between different studies. In spite of having highlighted some recurring patterns in the reported results, this review is, therefore, limited by the intrinsic differences of the studies reviewed.

Conclusion

Extract

Improved experimental reproducibility will be key to any advances in this field, and the development of new experimental procedures capable of measuring the small but profound way in which certain types of EMF exposure seem to affect our brain might help us to establish whether it is harmful and its therapeutic potential. We hope this work will help in improving our knowledge about the molecular dynamics of neuronal VGCs, which will be key both for any progress in the treatment of neurodegenerative diseases and for an advancement in the general understanding of the relationship between technological progress and cellular dynamics.

https://nyaspubs.onlinelibrary.wiley.com/doi/epdf/10.1111/nyas.14597

The post Effects of electromagnetic fields on neuronal ion channels: a systematic review appeared first on EMFSA.

Significant Cellular Viability Dependence on Time Exposition at ELF-EMF and RF-EMF In Vitro Studies

Editor — Sun, 21 Jul 2019 10:37:49 +0000

Int J Environ Res Public Health. 2019 Jun; 16(12): 2085.

Published online 2019 Jun 13. doi: 10.3390/ijerph16122085

Abstract

The human concern about the effect of electromagnetic fields (EMFs) has changed over time from the effects produced by EMFs of extremely low frequencies (ELFs) to the effects produced by exposure to a radio frequency (RF), with concerns shifting toward EMFs due to the development of new technologies and forms of communication. Previous studies have analysed the effects produced at different frequencies without considering in detail the effect of the time of exposure. Therefore, in the present study, we analysed in vitro the effect produced by a 100 µT EMF at different ELFs and exposure times in glioblastomas, as well as the effect produced in a fibroblast by an RF-EMF of 2.54 GHz. Our results indicate a significant time dependence in cell viability of fibroblasts exposed to an RF-EMF of 2.54 GHz and a non-time-dependent effect in cell viability of glioblastomas exposed to an ELF-EMF, highlighting the possible relation between frequency and time of exposure.

The main hypothesis of the study is that is that cell variability is correlated with frequency and time of exposure

Conclusion

In most of the in vitro studies that have been done with EMFs, the time of exposure has not been considered in detail, even though cellular responses, such as cell proliferation, viability and death, clearly vary between chronic and acute exposure.

Our results demonstrate a time dependence of NIH/3T3 cell viability when exposed to an RF-EMF of 2.54 GHz, which decreases with time to obtain a 71.12% decline in viability after 21 h of exposure.

On the other hand, our results for an ELF-EMF of 100 µT have demonstrated non-time-dependent effects. Frequency dependence effects were observed, obtaining a primary increase in cell viability at 50 Hz and a reduction in cell viability at 30 Hz, showing that even the recommended exposure level affects cell viability.

Therefore, the relationship between the frequency and time of exposure could determine the cellular response, demonstrating a need for further research.

Comments by EMFSA as noted from the study:

-The effect produced by an EMF depends on the cell line.

-There is a sex and species dependence in tumour development as per the NTP study.

-Clear evidence that RF-EMF produces changes in vitro and in vivo.

-There is no doubt that a significant cellular decrease occurs after 6 hours of exposure in NIH/3T3 cells but the authors point out that it is not clear whether the decrease in cell viability is related to an increase in mortality or to the antiproliferative properties of the EHF-EMF.

– The authors’ finding with NIH/3T3 cells cannot be completely compared with previous RF-EMF exposure results:

Few studies have been performed using a certified testing chamber
No recent studies have been done in vitro with fibroblasts at a frequency of 2.54 GHz.

– The results of the study show that an ELF-EMF at the recommended exposure level affects cell viability.

— According to the authors it is not enough to investigate the cellular response of other cancerous and non-cancerous cell lines at different power densities and frequency – but also according to their results the exposition time is fundamental.

The post Significant Cellular Viability Dependence on Time Exposition at ELF-EMF and RF-EMF In Vitro Studies appeared first on EMFSA.

Exposure Time Archives - EMFSA

Effects of electromagnetic fields on neuronal ion channels: a systematic review

Abstract

Significant Cellular Viability Dependence on Time Exposition at ELF-EMF and RF-EMF In Vitro Studies

Abstract

Conclusion

Comments by EMFSA as noted from the study: