Study type: Medical/biological study (experimental study)

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

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

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 2 h
Exposure 2: 50 Hz
Exposure duration: continuous for 2 h/day for 3 days
Exposure 3: 50 Hz
Exposure duration: continuous for 2 h/day for 2 weeks
Exposure 4: 50 Hz
Exposure duration: continuous for 2 h/day for 1 month

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 2 h
Exposure setup
Exposure source
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
Exposure duration continuous for 2 h/day for 3 days
Exposure setup
Exposure source
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
Exposure duration continuous for 2 h/day for 2 weeks
Exposure setup
Exposure source
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
Exposure duration continuous for 2 h/day for 1 month
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
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:

Study funded by

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