Study type: Medical/biological study (experimental study)

Improvement of spatial memory disorder and hippocampal damage by exposure to electromagnetic fields in an Alzheimer's disease rat model. med./bio.

Published in: PLoS One 2015; 10 (5): e0126963

Aim of study (acc. to author)

The effects of exposure of Alzheimer's disease model rats to a 50 Hz magnetic field on cognitive functions, histopathology and protein expression in the brain should be investigated.

Background/further details

Rats were divided into 4 groups: 1) exposure of healthy rats (n=15), 2) exposure of Alzheimer's disease model rats (n=14), 3) non-exposed Alzheimer's disease model rats (n=15), 4) non-exposed healthy rats (n=13; control group).
Rats were examined up to 5 days after termination of exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 hours/day for 60 days

General information

background magnetic field in room for non-exposed animals was below 400 nT during exposure

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 24 hours/day for 60 days
Exposure setup
Exposure source
Chamber boxes with 20 cm height and 50 cm square bottom
Setup two parallel coaxial circular coils with 70 cm height and 140 cm diameter were used and two modular breeding devices each comprising 4 boxes with 8 animals per box were used; MF intensity in breeding device was attenuating ringlike but was unchanged longitudal along the axis of the coils
Additional info non-exposed animals were kept in a separate room on the same floor as the exposed animals; both rooms shared the same ventilation system and humidity, light, temperature and air quality of the both rooms was equal
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 420 µT maximum measured - -
magnetic flux density 400 µT - measured - at 25 cm distance to point of max value
magnetic flux density 380 µT - measured - at the edge of the box

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)

All rats exposed to the magnetic field (groups 1 and 2) showed a significantly delayed weight gain compared to non-exposed rats (3 and 4).
In the Morris water maze, a partial improvement of the spatial memory and learning was observed in Alzheimer's disease model rats exposed to the magnetic field (group 2) compared to Alzheimer's disease model rats without exposure (group 3).
Histopathological damages were found in groups 1-3 15 minutes after the end of exposure, but the groups exposed to the magnetic field (groups 1 and 2) showed a partial recovery after 5 further days.
The expression rates of several proteins were significantly different in the groups 1-3 compared to the control group and in exposed Alzheimer's disease model rats (group 2) compared to non-exposed model rats (group 3). Identified proteins are involved in synaptic transmission, oxidative stress, protein degradation, energy metabolism, Tau protein aggregation and inflammation processes.
The authors conclude that exposure to a 50 Hz magnetic field could improve cognitive and histopathological symptoms of Alzheimer's disease model rats and that several molecular clues for further research could be identified.

Study character:

Study funded by

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