Study type: Medical/biological study (experimental study)

Exposure to 50 Hz magnetic field modulates GABA currents in cerebellar granule neurons through an EP receptor-mediated PKC pathway. med./bio.

Published in: J Cell Mol Med 2015; 19 (10): 2413-2422

Aim of study (acc. to author)

The effects of exposure of rat cerebellar granule neurons to 50 Hz magnetic fields on gamma aminobutyric acid (GABA) type A receptor ion channel activity and associated signal pathways should be investigated.

Background/further details

Cells were divided into the following groups: 1) exposure to a magnetic field of 0.2 mT for 60 and 120 minutes, 2) exposure to a magnetic field of 1 mT for 30 and 60 minutes, 3) sham exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for up to 120 min
Exposure 2: 50 Hz
Exposure duration: continuous for up to 60 min

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for up to 120 min
Exposure setup
Exposure source
Exposure room culture plates
Setup a pair of horizontal Helmholtz coils (20 cm in height and 20 cm in radius, each coil consisting of 150 turns of copper wire) was placed parallel to each other; the surfaces of the culture plates were perpendicular to the force lines of the alternating magnetic field; the magnetic field was homogeneous in exposure area
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.2 mT - measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for up to 60 min
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Reference articles

  • Wu X et al. (2014): Weak Power Frequency Magnetic Field Acting Similarly to EGF Stimulation, Induces Acute Activations of the EGFR Sensitive Actin Cytoskeleton Motility in Human Amniotic Cells.
  • Varani K et al. (2012): Effect of pulsed electromagnetic field exposure on adenosine receptors in rat brain.
  • Ongaro A et al. (2012): Electromagnetic fields (EMFs) and adenosine receptors modulate prostaglandin E(2) and cytokine release in human osteoarthritic synovial fibroblasts.
  • De Mattei M et al. (2009): Adenosine analogs and electromagnetic fields inhibit prostaglandin E2 release in bovine synovial fibroblasts.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Cells exposed to a magnetic field of 0.2 mT (group 1) for 120 min or of 1 mT (group 1) for 60 min showed significantly increased GABA type A receptor ion channel currents compared to sham exposed cells. No significant differences were obeserved at the respective earlier points in time. An activation of protein kinase A led to a slight decrease of the ion channel current, however, whereas a protein kinase C activation led to an increase of the currents comparable to the magnetic field exposure and the inhibition of protein kinase C blocked the current.
Western blot analysis indicated that the protein expression of phosphorylated protein kinase C was significantly increased in cells after 60 minutes of 1 mT exposure in comparison to sham exposed cells, which could subsequently be blocked by the addition of the prostaglandin E receptor inhibitor SC19220. SC19220 also significantly inhibited the magnetic field-induced elevation of the GABA type A receptors ion channel currents.
The authors conclude that exposure of rat cerebellar granule neurons to a 50 Hz magnetic field could increase the GABA type A receptor ion channel activity and that these effects might be mediated via prostaglandin E receptor 1-protein kinase C pathway.

Study character:

Study funded by

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