de Gannes FP, Billaudel B, Taxile M, Haro E, Ruffié G, Lévêque P, Veyret B, Lagroye I. (2009). Effects of head-only exposure of rats to GSM-900 on blood-brain barrier permeability and neuronal degeneration. Radiat Res. 172(3):359-367.
The blood-brain barrier (BBB) is important to regulate the transfer of nutrients and wastes from the blood to the brain and from the brain to the blood. It is also important in maintaining homeostasis for proper functioning of the neurons. There are concerns that radiofrequency field (RF) radiation may disrupt the functioning of the blood-brain barrier by increasing its permeability. Previous studies on the effects of RF on blood-brain barrier permeability showed mixed results.
The aim of the current study is to confirm a previous study which showed that the occurrence of brain damage (permeability of the blood-brain barrier and presence of dark neurons) 50 days after a single 2 hour exposure of rats to a GSM-900 mobile telephony signal.
The previous study had several shortcomings which warranted conducting the experiment using more controlled conditions. In the current study, twelve-week-old (240–280 g) male Fischer 344 rats were placed in a TEM cell and exposed head-only to GSM-900 signal for 2 hours at various brain-averaged specific absorption rates (SARs) (0, 0.14 and 2.0 W/kg). After exposure, rats were kept for 14 or 50 days in the animal facility. The animals were sacrificed and brain material was prepared for analysis. The brain tissues were examined for the presence of neuronal damage, blood-brain barrier leakage and apoptosis. The positive control animals were exposed to cold shock to induce brain damage.
The results showed no clear damage to the neurons of exposed animals. Experiments to study the effects on blood-brain barrier showed no statistically significant albumin leakage that was observed after exposure to GSM-900 at either brain-averaged SAR’s. A significant increase in albumin leakage was noticed in positive control rats receiving cold shock compared to control rats. With regard to apoptosis, no single apoptotic neuron was detected in any regions with any RF-radiation exposure condition tested.
The results of this study were in agreement with previous studies which showed no effect of RF radiation on blood-brain barrier but were in disagreement with a previous study that showed a positive effect which had several technical difficulties.