Huntington's disease is a genetic disease which leads to a gradual destruction of the striatum. In this experiment, the disease was simulated by administration of 3-nitropropionic acid as it is a commonly used model with similar brain damage and symptoms.
48 rats were equally divided into the six following groups (n=8): 1) cage control, 2) sham exposure, 3) exposure to the magnetic field, 4) administration of 3-nitropropionic acid, 5) administration of 3-nitropropionic acid and subsequent sham exposure and 6) administration of 3-nitropropionic acid and subsequent exposure to the magnetic field. All rats conducted behavioral tests afterwards and were finally sacrificed to remove their brains.
Exposure duration: continuous for 2 x 2 h/day ( in the morning and in the afternoon) for 21 days
|Distance between exposed object and exposure source||6 cm|
|Chamber||animals were placed in cylindrical plastic cages (10.5 x 10.5 x 3.5 cm) designed to keep them immobile during the exposure of their heads|
|Setup||pair of Helmholtz coils consisting of 1000 turns of 7 cm diameter enameled copper wire; coils placed above and under the rat's head; rat placed in a cylindrical plastic cage to keep it immobile during exposure|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||0.7 mT||-||-||-||-|
Sham exposure did not show any effects in the whole experiment, which means that no significant differences in all parameters were found between group 1 and 2 and between group 4 and 5. Group 3 showed significantly increased levels of neurotrophic factors compared to control, indicating a stimulation of neuronal growth. Group 4 showed significant differences in all measured parameters compared to control, including oxidative stress, cellular damage, neuronal loss and alterations in behavior. Finally, group 6 showed significant differences compared to group 4 in all parameters with a distinct trend of weakening the effects of 3-nitropropionic acid and approximation to control values.
The authors conclude that an exposure of rat head to a 60 Hz-magnetic field with 0.7 mT reduces brain injuries caused by 3-nitropropionic acid and thus showing its potential as a therapeutic tool.