Carbon-loaded Teflon electrodes for chronic EEG recordings in microwave research

Conventional metal electrodes can cause serious modification and intensification of the rate of energy absorption in tissues during exposure of animals to microwaves. Carbon-loaded Teflon with a conductivity close to that of tissue has been implanted and maintained for four to six months at cortical and subcortical locations in rabbits. The EEG and its spectrum as recorded from the carbon-loaded Teflon electrodes are comparable to those recorded from conventional metal electrodes. Histological examination showed good tissue compatibility. Recordings made during acute exposure of rabbits to microwave radiation (2450-MHz) at 100 mW/cm2 showed no electromagnetic interference. The results indicate that carbon-loaded Teflon electrodes can be implanted chronically to record the EEG in animals during the course of microwave radiation.