To determine whether brief pulsed microwave exposures altered susceptibility to pentylenetetrazol (PTZ, induces seizures by blocking the inhibitory effect of GABA as well as by a direct effect on neuronal membranes) seizures or the efficacy of chlordiazepoxide (CDZ) for counteracting PTZ seizures.
|Pulse width||2 µs|
|Repetition frequency||500 Hz|
|Distance between exposed object and exposure source||110 cm|
|Chamber||The antenna was a multiridged rectangular horn with a diagonal aperture of 20.5 cm radiating vertically downward into an anechoic chamber of 1.7 m x 2.6 m x 2.6 m.|
|Setup||Rats were placed in vented circular acrylic cages of 15.3 cm diameter and 9.5 cm height with 6 mm thick acrylic lids and floors.|
|Sham exposure||A sham exposure was conducted.|
|Additional info||Up to four rats could be exposed at a time at four positions of equal power density spaced about 3 λ apart. However, due to handling constraints, only two rats were exposed at a time.|
|power density||5 mW/cm²||-||measured||-||-|
|power density||10 mW/cm²||-||measured||-||-|
|SAR||1.5 W/kg||-||measured||-||± 0.1 W/kg|
|power density||15 mW/cm²||-||measured||-||-|
|power density||20 mW/cm²||-||measured||-||-|
The experiments failed to provide consistent evidence for an effect of 2.70 GHz pulsed microwave exposure up to 20 mW/cm² on PTZ-induced seizures or on the efficacy of CDZ for counteracting such seizures. One consistent result across all experiments was that pulsed microwaves elevated core temperatures and this was proportional to the power density. Microwave exposure counteracted the hypothermic effects of CDZ without altering its anti-seizure efficacy. This underscores the dissociation between thermal and pharmacological effects of microwave exposure.