Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat med./bio.

To study the effects of single (45 min) and repeated (ten daily 45-min sessions) microwave exposures on the concentration and affinity of benzodiazepine receptors in the hippocampus, cerebellum, and cerebral cortex of the rat.

The benzodiazepine receptors coupled to GABA receptors and chloride channels play a significant role in mediating stress and anxiety responses in animals. In addition, a separate experiment was done to investigate whether factors in the irradiation environment contribute to the effect of microwaves on benzodiazepine receptors: Rats were adapted to the exposure environment before exposure to microwaves. The animals were placed in waveguides, given food and water, and after 24 h were subjected to microwave or sham irradiation for 45 min.

• animal
• rat/Sprague-Dawley

After a single exposure, an increase in the concentration of receptor was observed in the cerebral cortex, but no significant effect was observed in the hippocampus or cerebellum. No significant change in binding affinity of the receptors was observed in any of the brain regions investigated. In animals subjected to repeated exposures, no significant change in receptor concentration was found in the cerebral cortex immediately after the last exposure, which may indicate an adaptation to repeated exposures. The results also show that handling and exposure procedures in the experiments did not significantly affect benzodiazepine receptors. Because benzodiazepine receptors in the brain are responsive to anxiety and stress, the data support the hypothesis that low-intensity microwave exposure can be a source of stress.