چكيده به لاتين
Magnetic therapy has always been of great interest to humans. In recent years electromagnetic fields have been used in wound and bone fracture healing, pain, inflammation and infection reduction, decreasing anxiety and depression, learning and memory enhancement and etc. every therapeutic method has it’s own cost and benefit. When a living organism is exposed to electromagnetic field, electrical currents are induced in the body, but the exact mechanism of their effects on different parts of the body is not yet clear. Due to their low cost and ease of use, in case of thorough evaluations and finding exact characteristics of a therapeutic radiation with no side effects, we can use electromagnetic field radiation as a main or auxiliary treatment.
In this study, 16 young male wistar rats (about 3 weeks of age) were randomly assigned to four groups: parallel exposure, perpendicular exposure, sham exposure and control group. Rats were exposed to 50 Hz parallel electromagnetic field radiation with magnetic flux density of 1.15 mT and 50 Hz perpendicular radiation with maximum magnetic flux density of 450T; 1 hour per day for 25 days. From 3rd day to 17th day after exposure period, field effects on psychological functions including anxiety, learning and memory were evaluated.
In parallel radiation, heating due to ohmic loss, makes the situation inconvenient for animals. The use of aluminum pulleys for windings transfers heat to the outside of solenoid and thus helps heat exchange.
For anxiety evaluation, elevated plus maze and light-dark box and for evaluating memory functions and learning, novel object recognition and T-maze behavioral tests were used.
In elevated plus maze, perpendicular exposure group had minimum number of entrance and spent time in open arms, hence they had maximum anxiety-like behavior; then there are parallel exposure, sham exposure and control group respectively. In light-dark box, parallel exposure group had minimum number of entrance and spent time in light part of the box, so they had maximum anxiety-like behavior; then there are sham exposure, perpendicular exposure and control group. In T-maze, perpendicular exposure group had the best memory function; then there are parallel group, sham exposure and control group respectively. In novel object recognition test, parallel exposure group spent more time studying the novel object, hence they had the best memory function; then there are perpendicular exposure, sham exposure and control group.
The results suggest that chronic extremely low frequency electromagnetic field exposure increases anxiety level in young rats but in memory functions and learning, both exposed groups were significantly better than sham exposed and control group.
