Anticonvulsant activity of clonazepam in experimental animals

Abstract
Clonazepam possessed the strongest anticonvulsant activity against various seizures induced by electroshock. Metrazol, picrotoxin and strychnine among anti-epileptic drugs and other benzodiazepines as investigated in rats and mice. The anti-Metrazol activity of clonazepam was much higher than against other types of experimental convulsions. Clonazepam suppressed EEG afterdischarges induced by stimulation of either dorsal hippocampus or amygdaloid complex of both freely moving rats and gallamine-immobilized cats. The drug had little effect on EEG afterdischarges following cerebral cortical stimulation in rats and on EEG arousal threshold in rats and cats. The drug markedly inhibited evoked potentials of the ventral hippocampus after stimulation of ipsilateral basolateral amygdala, but it did not change the evoked potentials of the ventral hippocampus after stimulation of the contralateral structure. The drug markedly enhanced the dorsal root reflex and decreased synaptic recovery more than did other benzodiazepines but had no effect on post-tetanic potentiation in spinal cats. The anti-convulsant activity of clonazepam is at least partly due to the inhibition of synaptic recovery and the enhancement of presynaptic inhibition.