Effects of kindling or brain stimulation on pentylenetetrazol-induced convulsion susceptibility

The effects of either kindling or nonkindling brain stimulation on pentylenetetrazol (PTZ)-induced convulsion susceptibility was assessed, using rats. The results show that repeated brain stimulation alone is sufficient to reduce the threshold dose of PTZ required to evoke a generalized convulsion, and that kindled convulsions do not significantly reduce the threshold further. However, kindled convulsions do increase the PTZ-induced convulsion duration and severity relative to that seen in stimulated or unstimulated animals. These results suggest that the increased convulsion susceptibility has two components that depend on different aspects of brain stimulation kindling.