GFAP expression in the rat brain following sub-chronic exposure to a 900 MHz electromagnetic field signal

Abstract

Purpose: The rapid development and expansion of mobile communications contributes to the general debate on the effects of electromagnetic fields emitted by mobile phones on the nervous system. This study aims at measuring the glial fibrillary acidic protein (GFAP) expression in 48 rat brains to evaluate reactive astrocytosis, three and 10 days after long-term head-only sub-chronic exposure to a 900 MHz electromagnetic field (EMF) signal, in male rats.

Methods: Sprague-Dawley rats were exposed for 45 min/day at a brain-averaged specific absorption rate (SAR) = 1.5 W/kg or 15 min/day at a SAR = 6 W/kg for five days per week during an eight-week period. GFAP expression was measured by the immunocytochemistry method in the following rat brain areas: Prefrontal cortex, cerebellar cortex, dentate gyrus of the hippocampus, lateral globus pallidus of the striatum, and the caudate putamen.

Results: Compared to the sham-treated rats, those exposed to the sub-chronic GSM (Global System for mobile communications) signal at 1.5 or 6 W/kg showed an increase in GFAP levels in the different brain areas, three and ten days after treatment.

Conclusion: Our results show that sub-chronic exposures to a 900 MHz EMF signal for two months could adversely affect rat brain (sign of a potential gliosis).

Keywords:

• astrocyte
• Glial fibrillary acidic protein (GFAP)
• electromagnetic field
• rat
• brain

Acknowledgements

The authors would like to acknowledge Maryse Marliere and Cray Valley (INERIS) for their technical assistance with the dose analysis and determination of SAR values. This work was funded by Project RFMemat, The Health and Radiofrequencies Foundation (2006–05), Pr 189 and RF chroTox DRC 02 – AP 07 of French Ministry of Ecology (MEDDAD).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.