On the elicitation of status epilepticus from previously kindled forebrain foci

While considerable research has concentrated on the neuroanatomical substrates of acute seizure activity, there is a relative lack of research concerned with the substratum of status epilepticus or sustained epileptiform activity. In the present study, a kindling based model of status epilepticus was used to investigate the responsiveness of the ventral hippocampus, dorsal hippocampus, caudate nucleus or olfactory bulbs to continuous high or low-intensity electrical stimulation. The results indicated structural differences in the type and severity of status epilepticus manifested. Specifically, the dorsal hippocampus was impervious to status epilepticus whilst the ventral hippocampus was capable of supporting convulsive and nonconvulsive status epilepticus, the olfactory bulb nonconvulsive status epilepticus and the caudate a stimulus bound form of continuous seizure. In general, a higher intensity of stimulation (i.e. higher current level) did not increase the probability of developing convulsive status epilepticus but was capable of eliciting nonconvulsive status epilepticus in the ventral hippocampus and olfactory bulbs. In the ventral hippocampus low-intensity stimulation was more efficacious in producing convulsive status epilepticus. Possible mechanisms and implications of these findings were discussed.