Hormonal influences on seizure kindling: the effects of post-stimulation ACTH or cortisone injections

Repeated application of brain stimulation can lead to a progressively augmenting electrical and behavioral response-- a phenomenon termed seizure kindling. In this experiment, stimulation was delivered once per day, and was followed by peripheral (intraperitoneal) administration of ACTH or cortisone. An intermediate or a high dose of either hormone (0.3 IU or 3.0 IU of ACTH/animal, 10 mg or 25 mg cortisone/animal) delayed the completion of kindling if administered shortly after each kindling stimulation. Lower doses (0.03 IU of ACTH or 2 mg of cortisone) had no significant effects. The high dose of ACTH or cortisone was no longer effective if administration was delayed more than 4 h after stimulation. Peripherally administered ACTH and cortisone can influence processes initiated by the brain stimulation which presumably underlie the augmentation of response to successive stimulations. This time-limited action is analogous to the effects of these hormones on memory consolidation.