To study the effects of UMTS radiofrequency electromagnetic fields on full brain exposed male rats in order to elaborate putative influences on stress hormone release and on hippocampal derived synaptic long-term potentiation and long-term depression as electrophysiological hallmarks for memory storage and memory consolidation.
|Exposure duration||continuous for 2 h|
|Setup||hexagonal double-cone waveguide placed above the six shielded exposure compartments; metal ribs with a gap of 6 mm between them fixed to the opposite walls of the inner and outer cone build into each compartment to concentrate the RF exposure; conic rat constrainers positioned inside the compartment so that the rat's brain was directly below the waveguide aperture|
|Sham exposure||A sham exposure was conducted.|
Comparison of cage control animals revealed significantly increased corticosterone and ACTH levels in the exposed and sham exposed groups which corresponded with generally decreased field excitatory postsynaptic potential slopes and amplitudes in hippocampal long-term depression and long-term potentiation.
Animals exposed at a SAR value of 2 W/kg did not differ from the sham exposed group in long-term depression and long-term potentiation experiments. In contrast, a significant reduction in long-term depression and long-term potentiation was observed at the SAR value of 10 W/kg. The data demonstrate that a rate of 2 W/kg displays no adverse impact on long-term depression and long-term potentiation, while 10 W/kg leads to significant effects on the electrophysiological parameters, which can be clearly distinguished from the stress derived background (due to immobilization).
The authors conclude that UMTS exposure with a SAR value in the range of 2 W/kg is not harmful to critical markers for memory storage and memory consolidation, however, an influence of UMTS at high energy absorption rates (10 W/kg, non-thermal) cannot be excluded. The data suggest that long-term activity-dependent synaptic plasticity is a putative target for the effect of electromagnetic fields of extraordinary high energy absorption rates in male adult Wistar rats.