Study type: Medical/biological study (experimental study)

Exposure to 50 Hz electromagnetic radiation promote early maturation and differentiation in newborn rat cerebellar granule neurons. med./bio.

Published in: J Cell Physiol 2005; 204 (2): 532-538

Aim of study (acc. to author)

To study the effect of electromagnetic field exposure at a frequency of 50 Hz on the development of cerebellar granule neurons.

Background/further details

Granule neurons were prepared from newborn rat cerebellum (8 days after birth).
These cells represent a good model to study cellular, chemical, or electrical properties. The life span of cerebellar granule neurons in culture is known to be relatively short, and after eight days cultures, cells become sensitive to glutamate. Immature cells are glutamate receptors negative. However during development, they exhibit an increase in the expression of glutamate receptors.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 5 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 5 days
Exposure setup
Exposure source
Setup Both the sample and the solenoid were kept in a CO2 incubator maintained at 37°C. Magnetic field deviation was within 5% inside the cylindrical exposure volume (14 cm x 17 cm) along the solenoid.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT effective value measured - -

Reference articles

  • Santoro N et al. (1997): Effect of extremely low frequency (ELF) magnetic field exposure on morphological and biophysical properties of human lymphoid cell line (Raji).

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Five days challenge to electromagnetic field exposures showed a 30% decrease of cells survival, while only 5% of mortality was reported for unexposed samples. Additionally, blocking the glutamate receptor (with the glutamate competitor MK-801) no toxicity effect after exposures and glutamate was detected.
The kainate-induced currents from 6 days old exposed cells exhibited a significant increase compared to control cells.
Western blot and RT-PCR analyses showed that electromagnetic field exposure of the cerebellar granule neurons induces a change in both glutamate receptor proteins and mRNAs expression compared to control.
In addition, the use of antibody raised against neurofilament protein (NF-200) revealed an increase in NF-200 synthesis in the exposed cells.
No differences in heat shock protein expression were revealed suggesting that exposed cells are not undergoing stress induced by heat effect.
All these data suggest that exposure to non-ionizing radiations contribute to a premature expression of glutamate receptors reducing the life span of cerebellar granule neurons, leading to a more rapid cell maturation.

Study character:

Study funded by

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