Inhibitory effects of acute exposure to low-intensity 60-Hz magnetic fields on electrically kindled seizures in rats

Abstract

The possibility that exposure to power-line frequency (60-Hz) magnetic fields might affect the development or characteristics of epileptic seizures in electrically kindled rats, was examined. Male adult rats with electrodes implanted in the basolateral amygdala were exposed to either a 60-Hz, 1.0 gauss magnetic field or to a sham field condition for 1 h prior to each daily brain stimulation session. EEG recordings were made to measure afterdischarge characteristics after each daily brain stimulation. Once the animals exhibited a full stage 5 seizure (after approximately 12-15 stimulations) a cross-over manipulation was used. On the last test day the sham field control group was exposed to the 60-Hz magnetic field for 1 h prior to brain stimulation and the experimental group, normally exposed to the magnetic fields, was exposed to the sham field condition. Examination of afterdischarge durations revealed a weak retardation in the development of kindling in the experimental group (P = 0.08). In the cross-over test, exposure to the 60-Hz magnetic fields resulted in a significant (P = 0.019) inhibition in afterdischarge duration relative to the rats exposed to the sham field conditions. These results clearly suggest an inhibitory effect of acute exposure to low intensity 60-Hz magnetic fields on the duration of afterdischarges in electrically kindled rats. Possible mechanisms for such an effect are discussed. © 1988.