Over the years, this laboratory has studied radio-frequency (rf) energy effects, such as evoked potentials in the brains of cats, conditioned responses in cats and monkeys, frog heart arrhythmia, and hearing phenomena in cats and humans. A few years ago, one of us (A.H.F.) discussed the possible mechanisms by which rf energy

Results of 2 experiments with a total of 18 female and 8 male Sprague-Dawley rats indicate that Ss spent more time in the halves of shuttle boxes that were shielded from illumination by 1.2-GHz microwave energy than in the unshielded halves. In Exp I, Ss avoided the energy when it was presented as 30-msec pulses with a pulse repetition rate of 100 pulses/sec (pps). The average power density was about .6 mW/cm2, and the peak power density was about 200 mW/cm2. In Exp II, the energy was presented both continuously and in pulse-modulated form (i.e., .5-msec exponentially decaying pulses at a rate of 1,000 pps). The average power density of the continuous energy was 2.4 mW/cm2, and the average power density of the pulse-modulated energy was .2 mW/cm2. The peak power density of the modulated energy was 2.1 mW/cm2. Results show that Ss avoided the pulsed energy, but not the continuous energy.