Study type: 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.

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

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

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: pulsed
Exposure duration: continuous for 2 h on postnatal day 7 or day 28

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
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 - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
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:

Study funded by

Related articles