Groups of four gerbils per cage were used: cage control, sham exposed group and three different exposure groups. The gerbils from sham exposed and exposed groups were subdivided into two groups, one sacrificed on the 7th day (immediately after the exposure) and the other one sacrificed on the 10th day from the beginning of the experiment.
Exposure duration: continuous for 7 days
|Setup||electromagnet with a regular laminated transformer core and a pole diameter of 9.5 cm; gerbils placed in 26 cm x 43 cm x 15 cm polycarbonate cages; two cages with 3-4 gerbils positioned simultaneously near the magnet, one on the left and the other on the right side with a distance between 20 cm and 40 cm|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||8.9 mT||maximum||measured||-||on the electromagnetic poles|
|magnetic flux density||0.5 mT||average over time||measured||-||in the cages|
|magnetic flux density||0.25 mT||average over time||measured||-||in the cages|
|magnetic flux density||0.1 mT||average over time||measured||-||in the cages|
In all gerbils, extremely low frequency magnetic field exposure significantly increased oxidative stress in all investigated brain regions. This effect increased in a magnetic flux density intensity dependent manner and was higher in middle-aged gerbils. Three days after exposure termination, the values of oxidative stress parameters showed a tendency to return to their control levels, particularly in 3-month-old gerbils.
These findings indicate that an extremely low frequency magnetic field exposure is able to induce oxidative stress in the brain of gerbils in an age- and magnetic field intensity-dependent manner.