ID Number		1209
Study Type		In Vivo
Model		900 MHz (GSM) acute and chronic exposure to adult and fetal mice and analysis of brain stress response gene expression (c-fos, hsp 32, hsp 70) as well as stress-induced microglial (e.g., GFAP).
Details		C57BL/6NTac transgenic Pim-1 mice exposed to 900 MHz (GSM) RF at 4 W/kg for 60 minutes (histological brain sections preserved from the same mice as used in the Repacholi replication study by Utteridge et al) were examined for c-fos expression. No effects of RF exposure, even at this fairly high SAR level, were observed. Restraint in the Ferris Wheel exposure system did, however, result in some c-fos elevation in the mouse brain. In a subsequent study, Pregnant Balb/C mice were exposed at 4 W/kg for 1 hour over a period of 19 days to 900 MHz (GSM) RF using the same exposure system as above. Fetal brain c-fos was measured using in situ hybridization and reported no differences in c-fos due to exposure. A 2009 publication also reported no changes in hsp-32 or hsp-70 in these same exposed fetal brains. There was also no effect due to the restraint when compared to cage control animals. In a study of chronic exposure, frozen brains from the PIM-1 bioassay replication study (Radiat Res 2002, 158:357-364) were used. Exposures in that study were 900 MHz GSM, whole body average SAR 4 W/kg, 60 min/day, 5 days/week, 104 weeks. The authors report no increase in c-fos in the cerebral-cortical and hippocampal areas of sectioned brains in exposed compared to sham. Both sham and exposed c-fos levels were equally elevated over cage controls in these regions, however, suggesting no habituation to the restraint stress. In subsequent studies from mice exposed as above, the authors report no increase in the water channel protein aquaporin-4, a marker suggesting no increase in blood brain barrier permeability. In these same animals (4 W/kg, 60 minutes / day for either 1 day or 5 days/wk for 104 wks), brain histological sections through the cingulate cortex and hippocampus revealed no indication of increased microglial cell function (that would be indicitive of increased inflammation and stress). AUTHORS' ABSTRACT: Court-Kowalski et al. 2015 (IEEE #5925): This study was designed to determine whether long-term (2 years) brain exposure to mobile telephone radiofrequency (RF) fields produces any astrocytic activation as these glia react to a wide range of neural perturbations by astrogliosis. Using a purpose-designed exposure system at 900 MHz, mice were given a single, far-field whole body exposure at a specific absorption rate of 4 W/kg on five successive days per week for 104 weeks. Control mice were sham-exposed or freely mobile in a cage to control any stress caused by immobilization in the exposure module. Brains were perfusion-fixed with 4% paraformaldehyde and three coronal levels immunostained for glial fibrillary acidic protein (GFAP). These brain slices were then examined by light microscopy and the amount of this immunomarker quantified using a color convolution method. There was no change in astrocytic GFAP immunostaining in brains after long-term exposure to mobile telephony microwaves compared to control (sham-exposed or freely moving caged mice). It was concluded that long-term (2 years) exposure of murine brains to mobile telephone RF fields did not produce any astrocytic reaction (astrogliosis) detectable by GFAP immunostaining.
Findings		No Effects
Status		Completed With Publication
Principal Investigator		Inst. Medical Veterinary Sci, Adelaide, Australia
Funding Agency		Australian Nat'l, MMF, GSM Association
Country		AUSTRALIA
References		Finnie, JW et al. Pathology, (2010) 42:151-154 Finnie, JW et al. Pathology, (2009) 41:473-475 Finnie, JW et al. Pathology, (2009) 41:276-279 Finnie, JW et al. Pathology, (2007) 39:271-273 Finnie, JW et al. Experimental Path., (2006) 38:333-335 Finnie, J Pathology., (2005) 37:231-233 Court-Kowalski, S et al. Bioelectromagnetics., (2015) 36:245-250
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