Rhythmic activity of the spike-and-wave type was induced by administration of metrazol (25 or 50 mg/kg s.c.) in male rats with implanted cortical electrodes. The animals were deprived of water and then allowed to lick water from a tube. Under control conditions they licked for 3-4 min without an interruption. Rhythmic metrazol activity deranged the licking; when this pathologic activity represented about one third of the time, the licking was fully blocked. We conclude that the impairment of highly motivated behaviour confirms the adequacy of the rhythmic metrazol activity as a model of human primary generalized seizures of the absence type.

Institute of Physiology Faculty of Medicine Charles University Prague

Early life exposure to clonazepam has both short- and long-term effects on seizures induced with pentylenetetrazol (PTZ)