Modification of seizure activity by electrical stimulation: III. Mechanisms

Daily electrical stimulation of the amygdala or hippocampus via implanted electrodes results in the development of a potentiality to trigger motor seizures in those areas. Arguments against several possible mechanisms underlying this development are discussed. Experiments are described which are intended to decide between increases in the strength of limbic-“motor system” connections or limbic-limbic connections as events underlying motor seizure development. It was found that stimulation of more than one area increases the rate of seizure development, whereas disrupting inter-limbic connections retards seizure development. It is concluded that motor seizure development is dependent upon the increased strength of limbic-limbic connections.