To investigate neural mechanisms affected by microwave exposure. The aim of the study was to investigate the brain site where endogenous opioids act to cause a decrease in cholinergic activity in the hippocampus by microinjecting the µ-opioid antagonist beta-funaltrexamine into the brain in an attempt to block inhibitory effect of microwaves.
|Exposure duration||continuous for 45 min|
|Pulse width||2 µs|
|Repetition frequency||500 Hz|
|Setup||The exposure system consisted of eight individual cylindrical waveguide exposure tubes made of galvanized wire screen and operating in TE11 mode. Each tube contained a plastic chamber to house a rat.|
|Sham exposure||A sham exposure was conducted.|
Acute exposure to pulsed 2450-MHz microwaves at a power density of 1 mW/cm² caused a decrease in cholinergic activity in the hippocampus of the rat. Microinjection of beta-funaltrexamine into the septum before exposure blocked this effect. These findings indicate that µ-opioid receptors in the septum mediate a microwave-induced decrease in cholinergic activity and support the authors' hypothesis that microwaves at a whole body SAR of 0.6 W/kg can activate endogenous opioids in the brain.