Medical/biological study (experimental study)

Effects of extremely low frequency electromagnetic field (50 Hz) on pentylenetetrazol-induced seizures in mice med./bio.

By: Fadakar K, Saba V, Farzampour S

Published in: Acta Neurol Belg 2013; 113 (2): 173-177

Aim of study (acc. to author)

To investigate the effects of exposure to extremely low frequency magnetic fields on the seizure induction in mice.

Background/further details

64 mice were divided into four groups (8 mice were sham exposed and 8 mice were magnetic field exposed per group): 1.) exposure/sham exposure for 1 day, 2.) exposure/sham exposure for 3 days, 3.) exposure/sham exposure for 2 weeks and 4.) exposure/sham exposure for 1 month. After exposure/sham exposure, pentylenetetrazol was injected into the mice. The injected dose needed to induce a seizure was measured.

Endpoint

effects on the neurological system: seizure susceptibility

Exposure

- 50 Hz
- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 2 h	magnetic flux density: 100 µT
Exposure 2: 50 Hz Exposure duration: continuous for 2 h/day for 3 days	magnetic flux density: 100 µT
Exposure 3: 50 Hz Exposure duration: continuous for 2 h/day for 2 weeks	magnetic flux density: 100 µT
Exposure 4: 50 Hz Exposure duration: continuous for 2 h/day for 1 month	magnetic flux density: 100 µT

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 2 h

Exposure setup

Exposure source	Helmholtz coils
Setup	two pairs of coaxially arranged Helmholtz coils with a diameter of 91.4 cm each, positioned 50 cm apart; coils oriented along the vector of the geomagnetic field
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	-

Exposure 2

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 2 h/day for 3 days

Exposure setup

Exposure source	same setup as exposure 1
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	-

Exposure 3

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 2 h/day for 2 weeks

Exposure setup

Exposure source	same setup as exposure 1
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	-

Exposure 4

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 2 h/day for 1 month

Exposure setup

Exposure source	same setup as exposure 1
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	-

Exposed system:

animal
mouse
whole body

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: seizure susceptibility (injected dose of pentylenetetrazol until seizure began)

Investigated system:

investigation on living organism

Time of investigation:

after exposure

Main outcome of study (acc. to author)

No significant differences were found between mice that were magnetic field exposed or sham exposed for 1 day, 3 days and 2 weeks. However, in mice exposed to a magnetic field for 1 month, the dose of pentylenetetrazol needed to induce a seizure was significantly higher compared to mice that were sham exposed for 1 month.
The authors conclude that long-term exposure to extremely low frequency magnetic fields could increase the seizure induction threshold in mice.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

not stated/no funding

Demir T et al. (2014): Investigation of the effects of magnetic field exposure on febrile seizure latency, seizure duration, and electroencephalographic recordings in a rat febrile convulsion model
Park WH et al. (2012): Inhibition of pentylenetetrazole-induced seizure in mice by using a 4 Hz magnetic field: a comparative study with a 60 Hz magnetic field
Varro P et al. (2009): Changes in synaptic efficacy and seizure susceptibility in rat brain slices following extremely low-frequency electromagnetic field exposure
Canseven AG et al. (2007): Pentylenetetrazol-induced seizures are not altered by pre- or post-drug exposure to a 50 Hz magnetic field
Kim J et al. (2004): Extremely low frequency magnetic field effects on premorbid behaviors produced by cocaine in the mouse
Sung JH et al. (2003): The influences of extremely low frequency magnetic fields on drug-induced convulsion in mouse
Keskil IS et al. (2001): No effect of 50 Hz magnetic field observed in a pilot study on pentylenetetrazol-induced seizures and mortality in mice
Potschka H et al. (1998): Effect of low-intensity 50-Hz magnetic fields on kindling acquisition and fully kindled seizures in rats
Ossenkopp KP et al. (1991): Inhibitory effects of powerline-frequency (60-Hz) magnetic fields on pentylenetetrazol-induced seizures and mortality in rats

Effects of extremely low frequency electromagnetic field (50 Hz) on pentylenetetrazol-induced seizures in mice med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Exposure 2

Main characteristics

Exposure setup

Parameters

Exposure 3

Main characteristics

Exposure setup

Parameters

Exposure 4

Main characteristics

Exposure setup

Parameters

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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