ATTEMPTS TO SIMULATE THE ASSOCIATION BETWEEN GEOMAGNETIC-ACTIVITY ANDSPONTANEOUS SEIZURES IN RATS USING EXPERIMENTALLY GENERATED MAGNETIC-FIELDS

In three separate experiments, chronic epileptic male rats (ns=24, 24, and 4) were exposed to experimental magnetic fields whose intensities were either constant or varied. The ripple frequency was always 7 Hz. Only exposure to a field with a constant intensity (700 nT) appeared to inhibit occurrence of the seizures. Although exposure to a field co nfiguration whose strength increased and decreased by fixed increments during the hour before feeding did nor affect the incidence of seizur es, exposure to these fields for 5 min. only once per hour (increments of 15 to 20 nT for 30 sec. to a maximum of 70 nT) during the previous night between midnight and 0800 hr. increased the proportion of seizu res following the presentation of food. An explanation is given for th e persistent antithetical effects of experimental magnetic fields and geomagnetic activity upon seizure phenomena.