| Popis: |
The brief electrical stimulation of limbic systems caused an after-discharge in these regions, and chronic stimulation produced generalized convulsions the so-called “kindling phenomenon”. In this experiment, effects of benzodiazepines on generalized convulsions and after-discharges produced by chronic stimulations of hippocampus or amygdala were studied. Electrodes were implanted into the hippocampus, amygdala and neocortex of Wistar strain male rats. After the recovery period, the hippocampus or amygdala was stimulated once per day by negative square waves (1.5 - 4.0 V;5 sec), which caused after-discharges. Generalized convulsions were produced at about 10th stimulation of amygdala or about 30th of hippocampus. Effects of diazepam and bromazepam (1,4 benzodiazepines) or clobazam (1,5 benzodiazepine) were tested in these animals. In amygdaloid kindled rats, diazepam at doses of 2.0 - 10.0 mg/kg i.p. dose-dependently suppressed the after-discharges and the convulsions were suppressed at high doses (5.0 and 10.0 mg/kg). Bromazepam at doses of 1.0 - 5.0 mg/kg i.p. dose-dependently suppressed the after-discharges and the convulsions in these rats. Clobazam at doses of 10 - 50 mg/kg i.p. dose-dependently suppressed the after-discharges and the convulsions were suppressed at high doses (20 and 50 mg/kg). In the hippocampal kindled rats, however, these 3 drugs showed less effects on the convulsions and the after-discharges. From these results, the relative potencies of anti-convulsive effects of bromazepam and clobazam, compared with diazepam, are 2 and 0.2, respectively, in hippocampal kindled rats and 5 and 0.3, respectively, in amygdaloid kindled rats. |
