Medical/biological study (experimental study)

Effects of short-duration electromagnetic radiation on early postnatal neurogenesis in rats: Fos and NADPH-d histochemical studies med./bio.

By: Orendacova J, Orendac M, Mojzis M, Labun J, Martoncikova M, Saganova K, Lievajova K, Blasko J, Abdiova H, Galik J, Racekova E

Published in: Acta Histochem 2011; 113 (7): 723-728

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Aim of study (acc. to author)

To study postnatal neurogenesis in the subventricular zone and rostral migratory stream of rats of both sexes.

Background/further details

At least two regions (the subventricular zone and hippocampal dentate gyrus) of the adult brain are responsible for proliferation and migration of neural precursor cells. The subventricular zone functions as the largest region of neurogenesis in the adult brain. Cells born in the subventricular zone migrate via a restricted pathway, called the rostral migratory stream, to the olfactory bulb where they differentiate into local interneurons.
Newborn postnatal day 7 (P7) and young adult rats (P28) were exposed to pulsed electromagnetic fields (each group n=10).

Endpoint

effects on the neurological system: postnatal neurogenesis

Exposure

- 2.45 GHz
- microwaves
- PW pulsed wave

Exposure	Parameters
Exposure 1: 2.45 GHz Modulation type: pulsed Exposure duration: continuous for 2 h on postnatal day 7 or day 28	power density: 2.8 mW/cm² minimum power density: 6.7 mW/cm² maximum

General information

For further information on the setup see also: Orendác M, Feník A, Mojzis M, Orendácová J. Biological effects of electromagnetic radiation on living systems with respect to the brain. Psychiatrie 2005 (Suppl.2):83-5.

Exposure 1

Main characteristics

Frequency	2.45 GHz
Type	electromagnetic field
Exposure duration	continuous for 2 h on postnatal day 7 or day 28

Modulation

Modulation type	pulsed

Exposure setup

Exposure source	not specified

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power density	2.8 mW/cm²	minimum	measured	-	-
power density	6.7 mW/cm²	maximum	measured	-	-

Additional parameter details

whole body exposure

Exposed system:

animal
rat/Wistar albino
whole body

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: postnatal neurogenesis (c-Fos immunoreactivity (as cellular stress marker; immunohistochemistry) and NADPH-diaphorase reaction (as marker for nitric oxide production; histochemistry); light microscopy)

Investigated system:

intact cell/cell culture

Investigated organ system:

brain/CNS

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data showed that short-term exposure induced increased c-Fos immunoreactivity in the cells of the subventricular zone of P7 and P28 rats. There were no c-Fos positive cells visible within the rostral migratory stream of exposed rats. This finding indicates that probably only the subventricular zone progenitor cells have the complete prerequisites necessary for the c-Fos signal transduction cascade.
Short-term exposure also caused earlier maturation of nitrergic cells (NADPH-diaphorase positive cells) within the rostral migratory stream of P7 rats. The NADPH-diaphorase positive cells appeared several days earlier than in the appropriate controls, and their number and morphology showed characteristics of adult rats. On the other hand, in the young adult P28 rats, electromagnetic field exposure induced morphological signs typical of early postnatal age (i.e. signs of dedifferentiation). These data indicate that electromagnetic field irradiation causes age-related changes in the production of nitric oxide, which may lead to different courses of the proliferation cascade in newborn and young adult neurogenesis.
In conclusion, the data indicate that a single dose of electromagnetic field irradiation represents a stressful event for proliferating cells, and they show that although proliferation runs during the whole of postnatal life, some age-and site-related specificities exist in the subventricular zone and rostral migratory stream neurogenic regions.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

VEGA (Scientific Grant Agency), Slovakia

Erdem Koc G et al. (2016): Neuroprotective effects of melatonin and omega-3 on hippocampal cells prenatally exposed to 900 MHz electromagnetic fields
Kim HS et al. (2015): Effect of whole-body exposure to the 848.5 MHz code division multiple access (CDMA) electromagnetic field on adult neurogenesis in the young, healthy rat brain
Watilliaux A et al. (2011): Effect of exposure to 1,800 MHz electromagnetic fields on heat shock proteins and glial cells in the brain of developing rats
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Orendacova J et al. (2007): Neurobiological effects of microwave exposure: a review focused on morphological findings in experimental animals
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