Mausset-Bonnefont AL, Hirbec H, Bonnefont X, Privat A, et al. (2004):
The authors studied the effects of RFR on the biochemistry of animals' brains. They used a heads-only exposure system and the RFR was emitted at 900 MHz frequency with pulse modulation. The SAR was 6 W/kg. In each experiment, rats were divided into 2 groups - one exposed to the RFR for 15 minutes, and one sham-exposed but restrained, also for 15 minutes. The neurotransmission systems of the brain were studied by examining the effects of the RFR on the excitatory, inhibitory, and neuromodulatory communications.
The excitatory system was studied via the effects on NMDARs, a subtype of glutamate receptors. The inhibitory system was investigated by GABAA receptors in the hippocampus. Modulatory systems were studied by examining dopamine transporters.
NMDARs showed a significant decrease in the cortex and striatum after exposure. GABAA receptors decreased in the hippocampus, and Dopamine receptors decreased in the cortex and increased in the striatum. A strong glial reaction was observed in the brain on microscopy. The rat general locomotor function was not altered in the short term.
The authors claim:
The authors do not believe that the results noted are due to thermal effects, but base this on experiments on a gel phantom and not on direct measurement. They state that their experiments should be repeated at lower power e.g. 2W/kg.