Medical/biological study (experimental study)

Extremely low-frequency magnetic exposure appears to have no effect on pathogenesis of Alzheimer's disease in aluminum-overloaded rat med./bio.

By: Zhang C, Li Y, Wang C, Lv R, Song T

Published in: PLoS One 2013; 8 (8): e71087-1-e71087-8

Aim of study (acc. to author)

To study whether or not an extremely low-frequency magnetic field exposure and aluminium treatment have synergistic effects on Alzheimer's disease pathogenesis by investigating the effects of extremely low-frequency magnetic field exposure with or without chronic aluminium treatment in rats.

Background/further details

Rats were divided into the following groups (each group n=10): 1.) sham exposure, 2.) oral aluminium administration, 3.) magnetic field exposure with oral aluminium administration, or 4.) magnetic field exposure without oral aluminium administration. The experiments were repeated three times.

Endpoint

effects on the neurological system: pathogenesis of Alzheimer's disease

Exposure

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 12 weeks	magnetic flux density: 100 µT

General information

Rats of the control groups were placed in a geomagnetic environment (ambient magnetic field (50 Hz) <400 nT; geomagnetic field 9-32 µT)

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 12 weeks

Exposure setup

Exposure source	Helmholtz coils
Chamber	rats were housed in plastic cages
Setup	pair of Helmholtz coils (diameter: 1400 mm); rats placed in the center of the coils; magnetic field direction was vertical; room temperature 23±1°C

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	-	-	-

Exposed system:

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: levels of beta-amyloid protein in hippocampus and cerebral cortex of 6 rats (radioimmunoassay); aluminium content in the cortex (inductively coupled plasma atomic emission spectrometry (ICP-AES)); brain morphology of 4 rats (hippocampal CA1 area and cortical region; number of neurons; hematoxylin-eosin staining)
cognitive/behavioral endpoints: spatial cognition (Morris water maze)
body weight; food and water intake

Investigated system:

tissue slices
tissue homogenates (cerebral cortex and hippocampus)
investigation on living organism

Investigated organ system:

brain/CNS

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

After 12 weeks, aluminium groups (groups 2 and 3) showed learning and memory impairments as well as morphological changes in the brain, including neuronal cell loss and a high density of beta-amyloid protein in the hippocampus and cerebral cortex. Extremely low-frequency magnetic exposure alone (group 4) showed no significant effect on Alzheimer's disease pathogenesis. Co-exposure of extremely low-frequency magnetic field and aluminium (group 3) did not induce more damage than aluminium treatment alone (group 2).
The data showed no evidence of any association between extremely low-frequency magnetic exposure exposure (100 µT, 50 Hz) and Alzheimer's disease, and extremely low-frequency magnetic field exposure did not influence the pathogenesis of Alzheimer's disease induced by aluminium overload.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

National Natural Science Foundation (NSFC), China
State Key Program of National Natural Science of China

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