Study type: Medical/biological study (experimental study)

Effects of extremely low-frequency magnetic field in the brain of rats med./bio.

Published in: Brain Res Bull 2006; 68 (5): 355-360

Aim of study (acc. to author)

To study the effect of an extremely low frequency magnetic field on antioxidant defense system and the production of reactive oxygen species and nitric oxide in the brain of adult male rats following a 7-day exposure.

Background/further details

12 rats were divided in two groups (exposed and sham exposed).



Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 7 days

Exposure 1

Main characteristics
Frequency 50 Hz
Exposure duration continuous for 7 days
Exposure setup
Exposure source
Distance between exposed object and exposure source 20 cm
Chamber Plastic cages with standard dimensions (26 cm x 43 cm x 15 cm) were covered with plexiglas plates and fixed to polystyrene foam. Each experimental group was divided into two subgroups that were simultaneously exposed (or sham-exposed). The center of each cage was 20 cm from the poles of the core on the respective side of an electromagnet. Sham-exposed animals were subjected to the same procedure as the exposed ones, but the source of the field was not activated.
Setup A solenoid type electromagnet with a regular laminated transformer core and pole dimensions 9.5 cm x 9.5 cm was used for generating the magnetic field.
Additional info Magnetic force lines were parallel to the horizontal component of the local geomagnetic field. Deviation of the geomagnetic field measured by a proton magnetometer was within the normal range. The background magnetic field did not exceed 10-5 mT.
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT spatial average measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Electromagnetic field exposure changed the values of all parameters examined: Superoxide radical content was increased in all brain structures. Superoxide dismutase enzyme activity was significantly increased in the basal forebrain. Production of nitric oxide varied among the brain structures (highest production in the frontal cortex and basal forebrain). Compared to sham-exposed rats, antioxidative defense was sufficient to protect brain structures of exposed rats against lipid peroxidation, except for the basal forebrain and the frontal cortex.
The data indicate that a 7-day exposure to extremely low frequency magnetic field can be harmful to the brain.

Study character:

Study funded by

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