6 groups of rats were examined (n= 15 per group): 1.) sham exposure for 2 weeks, 2.) sham exposure for 4 weeks, 3.) exposure to an electric field, 12 kV/m for 2 weeks, 4.) exposure to an electric field, 18 kV/m for 2 weeks, 5.) exposure to an electric field, 12 kV/m for 4 weeks and 6.) exposure to an electric field, 18 kV/m for 4 weeks.
At the end of the exposure/sham exposure period mismatch negativity responses were recorded in anesthetized rats. Afterwards, rats were killed and brain tissues were removed.
|Chamber||rats were exposed in plastic cages|
|Setup||parallel copper plates (50 x 80 cm) were plated with zinc (2-mm thickness); corners of parallel plates were rounded to produce an uniform electric field; plates were placed upright on wooden stands and positioned parallel to each other; plastic cage was placed between plates; plates were spaced at 50 cm distance|
|Sham exposure||A sham exposure was conducted.|
|Additional info||maximum background magnetic field was 0.1 µT (measured), homogeneity and uniformity of electric field was measured (maximum variation less than 1 %)|
In all exposure groups, the lipid peroxidation was significantly increased compared to the corresponding sham exposure groups. In comparison to the control group, the content of carbonyl groups was significantly increased in group 4 (18 kV/m for 2 weeks), group 5 (12 kV/m for 4 weeks) and group 6 (18 kV/m for 4 weeks). However, no apoptotic cells were found in any of the groups.
In group 6 (18 kV/m for 4 weeks), the mismatch negativity amplitude was significantly decreased in comparison to the 4 weeks sham exposure group. In group 3 (12 kV/m for 2 weeks) and group 4 (18 kV/m for 2 weeks), the mismatch negativity latency was significantly increased compared to the 2 weeks sham exposure group.
The authors conclude that exposure to a 50 Hz-electric field could have an influence on mismatch negativity component of event-related potentials in rats and that these effects could be due to oxidative stress in the rat's brain.