50 Hz alternating extremely low frequency magnetic fields affect excitability, firing and action potential shape through interaction with ionic channels in snail neurones

Moghadam, Mehri Kaviani; Firoozabadi, Saied Mohammad; Janahmadi, Mahyar

doi:10.1007/s10669-007-9143-3

Cited by 15 publications

(10 citation statements)

References 30 publications

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“…/K ? pump (Rosen and Lubowsky 1990;McLean et al 1995;Ye et al 2004;Moghadam et al 2008Moghadam et al , 2011Yang et al 2011). Such findings, although not excluding other mechanisms, indicate that static and alternating magnetic fields ranging from microtesla to tesla strength may involve the Na ?…”

Section: Pathways Involved In Magnetic Field Actionmentioning

confidence: 84%

“…There are reports that SMFs (of moderate, millitesla strength) can influence the membrane properties of invertebrate and vertebrate neurons. Neuronal properties affected by magnetic field-induced changes include input resistance (Balaban et al 1990), AP firing (Rosen and Lubowsky 1990;McLean et al 1995), AP amplitude (Ye et al 2004), properties of voltage-gated potassium channels (Jie-Fei et al 2007), and membrane resting potential (Moghadam et al 2008). The mechanisms underlying the effects of a magnetic field on neuronal membranes are still not entirely clear.…”

Section: Introductionmentioning

confidence: 99%

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Involvement of Na+/K+pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field

et al. 2012

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The spontaneously active Br neuron from the brain-subesophageal ganglion complex of the garden snail Helix pomatia rhythmically generates regular bursts of action potentials with quiescent intervals accompanied by slow oscillations of membrane potential. We examined the involvement of the Na(+)/K(+) pump in modulating its bursting activity by applying a static magnetic field. Whole snail brains and Br neuron were exposed to the 10-mT static magnetic field for 15 min. Biochemical data showed that Na(+)/K(+)-ATPase activity increased almost twofold after exposure of snail brains to the static magnetic field. Similarly, (31)P NMR data revealed a trend of increasing ATP consumption and increase in intracellular pH mediated by the Na(+)/H(+) exchanger in snail brains exposed to the static magnetic field. Importantly, current clamp recordings from the Br neuron confirmed the increase in activity of the Na(+)/K(+) pump after exposure to the static magnetic field, as the magnitude of ouabain's effect measured on the membrane resting potential, action potential, and interspike interval duration was higher in neurons exposed to the magnetic field. Metabolic pathways through which the magnetic field influenced the Na(+)/K(+) pump could involve phosphorylation and dephosphorylation, as blocking these processes abolished the effect of the static magnetic field.

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Section: Pathways Involved In Magnetic Field Actionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Involvement of Na+/K+pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field

et al. 2012

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“…The brain slices are then set up to a patch‐clamp to record electrophysiological characteristics after an incubation process (Balassa et al, ; Manikonda et al, ). The second method involves stimulating dissected brain slices alone in an external stimulation device, and then moving the tissue to the patch‐clamp to record electrophysiological characteristics (Bawin, Satmary, Jones, Adey, & Zimmerman, ; Moghadam, Firoozabadi, & Janahmadi, ; Zheng, Dou, Gao, Dong, & Li, 2016). The experimental slices will go through a few minutes of the interval from the end of the magnetic stimulation to the beginning of the patch clamp recording.…”

Section: Introductionmentioning

confidence: 99%

Modulating effects of on‐line low frequency electromagnetic fields on hippocampal long‐term potentiation in young male Sprague‐Dawley rat

Dong

Zheng

et al. 2018

J of Neuroscience Research

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The low frequency electromagnetic fields (LF-EMFs) are attracting more attention and studied deeply because of their effects on human health and biology. Recent reports indicate that exposure of rats to LF-EMFs induces persistent changes in neuronal activity. The studies used the following standard methods: the rats or rat brain slices were first stimulated in an external electromagnetic exposure system, and then moved to a patch clamp perfusion chamber to record electrophysiological characteristics (off-line magnetic exposure). However, this approach is susceptible to many disturbances, such as the effects of brain slice movements. In this paper, we describe a novel patch-clamp setup which is modified to allow accurate on-line LF-EMFs stimulation. We performed the computational simulations of the stimulation coils to describe the uniformity of the distribution of the on-line magnetic field. The 0.5, 1, 2 mT magnetic field of 15 Hz, 50 Hz, and 100 Hz was produced and applied to slices to study the effect of LF-EMFs on synaptic plasticity. We demonstrated that the slope of field excitatory postsynaptic potentials (fEPSPs) decreased significantly under the priming on-line uninterrupted or pulsed sinusoidal LF-EMFs stimulation. In the present study, we investigated whether LF-EMFs can induce long-term potentiation (LTP) in male Sprague-Dawley rat hippocampal slices in vitro. Interestingly, these results highlight the role of 100 Hz pulsed sinusoidal LF-EMFs only as a modulator, rather than an LTP inducer.

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“…These physiological responses through their influence on brain function are harmful, leading to deterioration of the quality of life; thus, MF exposure is an important biological indicator to be considered from the perspective of human body protection. Regarding the influence of low-intensity power frequency MFs on brain function, great interest has been gained and numerous findings have been obtained from various recent studies with human volunteers (Marino et al, 2004 ; Legros et al, 2012 , 2015 ), experimental animals (Manikonda et al, 2007 ; Szemerszky et al, 2010 ; Balassa et al, 2013 ; Rauš et al, 2013 , 2016 ; Salunke et al, 2014 ; Elmas and Comlekci, 2015 ), and cultured cells and tissues (Azanza et al, 2002 , 2013 ; Manikonda et al, 2007 ; Moghadam et al, 2008 , 2011 ; Varró et al, 2009 ; Moretti et al, 2013 ; Gramowski-Voß et al, 2015 ; Yang et al, 2015 ); however, the thresholds of neuronal modulation and implicated mechanisms by MF exposure are still under investigation. In addition, it has been recommended in the environmental health criteria (EHC) published by the World Health Organization (WHO) that the mechanism and threshold in the nervous system should be explained using cultured cells and theoretical models (World Health Organization, 2007 ).…”

Section: Introductionmentioning

confidence: 99%

Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

et al. 2018

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High-intensity and low frequency (1–100 kHz) time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz), a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF), and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA)-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms), 50 Hz, sinusoidal wave, 6 s), the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI); subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field) in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that the potentiation of neuronal activity after 400 mT hPF-MF exposure was related to the depression of autonomous activity of pacemaker-like neurons. Our results indicated that the synchronized bursting activity was increased by hPF-MF exposure (E-field: >0.3 V/m), and the response was due to reduced inhibitory pacemaker-like neuronal activity.

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50 Hz alternating extremely low frequency magnetic fields affect excitability, firing and action potential shape through interaction with ionic channels in snail neurones

Cited by 15 publications

References 30 publications

Involvement of Na+/K+pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field

Involvement of Na+/K+pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field

Modulating effects of on‐line low frequency electromagnetic fields on hippocampal long‐term potentiation in young male Sprague‐Dawley rat

Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

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