Effect of locus ceruleus stimulation on the development of kindled seizures.

The effects of locus ceruleus stimulation on amygdala kindling development were investigated. Twenty to thirty minutes of locus ceruleus stimulation was delivered prior to each amygdala kindling session. Locus ceruleus-stimulated animals spent a significantly longer time in stage 1 than did nonstimulated or reticular formation stimulated controls. However, the total number of stimulations to produce the first stage 5 did not differ between groups. The afterdischarge duration in locus ceruleus-stimulated animals increased even though the behavioral stages did not progress. There appeared to be an uncoupling of the electrographic and behavioral manifestations of the kindling process in the locus ceruleus-stimulated animals. These data support the view of an inhibitory role of the central noradrenergic system in the development of kindled seizures.