Weanling male rats fed a low magnesium diet for 14 days were protected from audiogenic seizures by administration of phenobarbital and diphenylhydantoin. Amphetamine, levo-dopa, and magnesium chloride injected 45 minutes prior to testing did not prevent the seizures. In contrast to weanling male rats which became mortally seizure prone, 3--5 week-old female rats fed a low magnesium diet for 17--21 days varied as to their susceptibility to audiogenic seizures. If thrown into seizures by a loud noise, the females frequently could be revived for subsequent testing, thus affording the opportunity to design experiments using fewer animals.