Medical/biological Study (experimental study)

The Effects of Single and Repeated Exposure to 2.45 GHz Radiofrequency Fields on c-Fos Protein Expression in the Paraventricular Nucleus of Rat Hypothalamus. med./biol.

PubMed Entry

Journal web site

Aim of study (according to author and editor)
To study the effects of radiofrequency exposure resulting in non-thermal (< 4 W/kg) specific absorption rates on c-Fos expression in the paraventricular nucleus (of the hypothalamus) of rats.
Background/further details:
60 female rats were divided into the following groups: 1) 20 rats were divided into three subgroups and exposed at 0, 3 and 12 W for 30 min. The rats were killed 90 min following exposure (when maximum c-Fos protein expression occurs). 2) 20 rats were divided into three subgroups and exposed at 0, 3 and 12 W for 30 min. The rats were killed 24 h following exposure. 3) 20 rats were exposed at 3 W for 30 min per day for a total of ten times in a two week period.

Endpoint

• effects on the neurological system: c-Fos expression in different regions of the paraventricular nucleus of the hypothalamus (as marker for neuronal activation)

Exposure
General category: radio frequency field, 2.45 GHz

Field characteristics	Parameters
field 1: 2.45 GHz exposure duration: continuous for 30 min	power: 3 W electric field strength: 40.28 V/m SAR: 0.0776 W/kg mean value (brain) SAR: 0.041 W/kg mean value (whole body) SAR: 0.22 W/kg peak value (1 g) (brain) SAR: 0.203 W/kg peak value (1 g) (whole body)
field 2: 2.45 GHz exposure duration: continuous for 30 min/day on 10 times during 2 weeks	power: 3 W electric field strength: 40.28 V/m SAR: 0.0776 W/kg mean value (brain) SAR: 0.041 W/kg mean value (whole body) SAR: 0.22 W/kg peak value (1 g) (brain) SAR: 0.203 W/kg peak value (1 g) (whole body)
field 3: 2.45 GHz exposure duration: continuous for 30 min	power: 12 W electric field strength: 80.56 V/m SAR: 0.301 W/kg mean value (brain) SAR: 0.16 W/kg mean value (whole body) SAR: 0.901 W/kg peak value (1 g) (brain) SAR: 0.791 W/kg peak value (1 g) (whole body)

Exposed system:
animal (species/strain): rat/Sprague-Dawley
whole body exposure

Methods
Endpoint/Measurement parameters/Methodology

• effects on the neurological system: c-Fos expression in different regions of the paraventricular nucleus (lateral magnocellular, medial parvocellular and ventral or lateral parvocellular; number of c-Fos-positive neurons; immunohistochemistry)

Main outcome of study (according to author)
A high SAR value induced an increase of the c-Fos expression 90 min or 24 h after exposure, and a low SAR value resulted in higher c-Fos expression than in control rats after 24 h. Repeated irradiation at 3 W increased cellular activation of the paraventricular nucleus by more than 100% compared to animals subjected to acute exposure or to repeated sham exposed animals.
The data suggest that the paraventricular nucleus is sensitive to 2.45 GHz microwave exposure at non-thermal SAR levels.

(Study character: medical/biological study, experimental study, full/main study)

Study funded by

• Xunta de Galicia, Spain

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