Study type: Medical/biological study (experimental study)

Neuroprotective effects of extremely low-frequency electromagnetic fields on a Huntington's disease rat model: effects on neurotrophic factors and neuronal density. med./bio.

Published in: Neuroscience 2012; 209: 54-63

Aim of study (acc. to author)

The effects of a chronic head exposure of rats to a 60 Hz magnetic field on the brain and the symptoms of Huntington's disease should be investigated with respect to a potential therapeutic use.

Background/further details

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.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous for 2 x 2 h/day ( in the morning and in the afternoon) for 21 days

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration continuous for 2 x 2 h/day ( in the morning and in the afternoon) for 21 days
Exposure setup
Exposure source
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.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.7 mT - - - -

Reference articles

  • Feria-Velasco A et al. (1998): Neuronal differentiation of chromaffin cells in vitro, induced by extremely low frequency magnetic fields or nerve growth factor: a histological and ultrastructural comparative study.
  • Drucker-Colin R et al. (1994): Comparison between low frequency magnetic field stimulation and nerve growth factor treatment of cultured chromaffin cells, on neurite growth, noradrenaline release, excitable properties, and grafting in nigrostriatal lesioned rats.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

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.

Study character:

Study funded by

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