Study type: Medical/biological study (experimental study)

Response of hippocampal neurons and glial cells to alternating magnetic field in gerbils submitted to global cerebral ischemia. med./bio.

Published in: Neurotox Res 2013; 23 (1): 79-91

Aim of study (acc. to author)

To investigate whether exposure to an extremely low-frequency magnetic field affects the outcome of post-ischemic damage in the hippocampus of Mongolian gerbils.

Background/further details

Cerebral ischemia was induced by surgical occlusion of both common carotid arteries for 10 min. Adult (3-month-old) male gerbils were divided into six groups: 1.) intact controls (n=3), 2.) sham operated (n=6), 3.) sham exposure (n=6), 4.) exposure (n=9), 5.) ischemia + sham exposure (n=9), and 6.) ischemia + exposure (n=9). All groups were subdivided into two groups and histological analyses were performed immediately at the end of exposure (on day 7) and 7 days after cessation of exposure (on day 14), respectively.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 7 days

General information

Animals were divided into the following groups: i) intact controls ii) sham operated iii) sham exposure iv) exposure v) ischemia + sham exposure vi) ischemia + exposure

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 7 days
Exposure setup
Exposure source
Setup two 26 cm x 43 cm x 15 cm cages with 3 - 4 animals placed at either side of the electromagnet so that the cage's center was at 20 cm distance from it
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2 mT maximum measured - 0.2 - 2.0 mT
magnetic flux density 0.5 mT average over time measured - at the cage's center

Reference articles

  • Raus S et al. (2012): Extremely low frequency magnetic field induced changes in motor behaviour of gerbils submitted to global cerebral ischemia.
  • Nikolic LM et al. (2010): Effect of alternating the magnetic field on phosphate metabolism in the nervous system of Helix pomatia.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Exposure to extremely low frequency magnetic fields alone did not induce any morphological changes in the hippocampus, while 10-min global cerebral ischemia led to neuronal death, especially in the CA1 region of the hippocampus.
Ischemic gerbils exposed to extremely low frequency magnetic fields (group 6) had a significantly lower degree of cell loss in the hippocampus and greater responses of astrocytes and microglial cells than post-ischemic gerbils with shamexposure (group 5) at the end of the 7-day exposure period. A similar response was observed on the seventh day after cessation of exposure (day 14, delayed effect); however, differences were low and the results statistically non-significant.
The authors conclude that exposure to extremely low frequency magnetic fields has possible neuroprotective function in the hippocampus, as the most sensitive brain structure in the model of global cerebral ischemia, through reduction of neuronal death and activation of astrocytes and microglial cells.

Study character:

Study funded by

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