Study type: Medical/biological study (experimental study)

Effects of short term and long term extremely low frequency magnetic field on depressive disorder in mice: involvement of nitric oxide pathway. med./bio.

Published in: Life Sci 2016; 146: 52-57

Aim of study (acc. to author)

The effects of exposure of mice to a 50 Hz magnetic field on depressive-like behavior and the role of nitric oxide should be investigated.

Background/further details

NG-nitroarginine methyl ester (L-NAME) was used to exert an anti-depressive effect. It was diluted in physiological saline and administered intraperitoneally (30 mg/kg) after exposure.
72 male mice were divided into the following groups (n=9 each): 1) acute exposure, 2) chronic exposure, 3) acute exposure and administration of L-NAME, 4) acute exposure and administration of saline (sham administration). For each group, a separate sham exposure group was used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 2 hours
Exposure 2: 50 Hz
Exposure duration: continuous for 2 hours/day for 2 weeks (6 days/week, 1 day break)

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 2 hours
Additional info acute exposure
Exposure setup
Exposure source
Chamber plexiglass cage
Setup two pairs of coaxially arranged Helmholtz coils with winding embedded in a plexiglass frame; the diameter of each coil was 91.4 cm; the distance between the coils in the pairs was 50 cm and there were 60 turns of 2.5 mm copper wire oriented along the vector of the geomagnetic field; the centrally horizontal MF was homogenous in the plexiglass cage with 4-5 animals (groups were divided); the temperature during exposure did not exceed 27 °C
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT effective value measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 2 hours/day for 2 weeks (6 days/week, 1 day break)
Additional info chronic exposure
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT effective value measured - -

Reference articles

  • de Bruyn L et al. (2010): Effect of long-term exposure to a randomly varied 50 Hz power frequency magnetic field on the fertility of the mouse.
  • Lee BC et al. (2004): Effects of extremely low frequency magnetic field on the antioxidant defense system in mouse brain: a chemiluminescence study.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Chronic exposure (group 2) significantly reduced depressive-like behaviour compared to the sham exposure, while acute exposure (group 1) did not show significant differences compared to the sham exposure.
However, acute exposure in combination with L-NAME (group 3) significantly increased the depressive-like behaviour compared to the respective sham exposure and thus negating the anti-depressing effect of L-NAME.
Locomotor activity did no show any significant differences between the groups.
The authors conclude that chronic exposure of mice to a 50 Hz magnetic field could alter depressive-like behavior in mice. The reversion of the anti-depressive effect of L-NAME indicates a possible increase of nitric oxide in the brain due to the magnetic field exposure.

Study character:

Study funded by

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