Study type: Medical/biological study (experimental study)

Deficits in water maze performance and oxidative stress in the hippocampus and striatum induced by extremely low frequency magnetic field exposure. med./bio.

Published in: PLoS One 2012; 7 (5): e32196

Aim of study (acc. to author)

To study the effects of chronic extremely low frequency magnetic field exposure of mice on habit learning which is dependent on striatum, and on spatial learning which is dependent on hippocampus, as well as to evaluate some parameters indicative for oxidative stress in these two structures.

Background/further details

72 male mice were divided into three groups (each group n=24): one sham exposure group and two exposure groups (1 mT and 0.1 mT).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 4 h/day for 12 weeks
Exposure 2: 50 Hz
Exposure duration: continuous for 4 h/day for 12 weeks

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 4 h/day for 12 weeks
Exposure setup
Exposure source
Setup coil of four layers of 250 turns of 1.68 mm copper wire wrapped horizontally around a 70 cm x 40 cm x 43 cm plastic frame; exposure area inside the coil (60 cm x 30 cm x 43 cm); mice were housed in pairs in plexiglas cages (50 cm x 25 cm x 25 cm) on a freestanding wood
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 4 h/day for 12 weeks
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.1 mT - measured - -

Reference articles

  • Sun H et al. (2010): Effects of prenatal exposure to a 50-Hz magnetic field on one-trial passive avoidance learning in 1-day-old chicks.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

There was no significant difference in body weight gain and locomotor activity across the three groups. However, animals exposed to the extremely low frequency magnetic field (1 mT) took longer to find the platform in the water maze compared with the other two groups. No significant effect was found in animals exposed at 0.1 mT.
Extremely low frequency magnetic field exposure (0.1 mT) did not result in the development of oxidative stress in mice hippocampus or striatum. However, exposure at 1 mT induced oxidative stress in mice hippocampus and striatum: The levels of malondialdehyde were significantly increased compared with the other two groups. The values of catalase and glutathione peroxidase enzyme activities as well as the total antioxidant capacity were significantly decreased compared with the other two groups.
In conclusion, extremely low frequency magnetic field exposure (1 mT) induced oxidative stress in the hippocampus and striatum and impaired hippocampal-dependent spatial learning and striatum-dependent habit learning. The data provide evidence for the association between the impairment of learning and oxidative stress in hippocampus and striatum induced by extremely low frequency magnetic field exposure.

Study character:

Study funded by

Related articles