EFFECTS OF ACUTE TREATMENT AND LONG-TERM TREATMENT WITH MK-801 AGAINST AMYGDALOID-KINDLED SEIZURES IN RATS

Effects of both acute and long-term treatments with a non-competitive NMDA-antagonist, MK-801, were studied in rats in order to investigate whether NMDA receptors would be involved in the maintenance of kindlin g. Intraperitoneally administered MK-801 at doses of 0.5, 1.0 and 2.0 mg/kg inhibited fully amygdaloid kindled seizures (stage 5) behavioral ly and significantly reduced the duration of after discharge and posti ctal spikes in a dose-dependent manner. Long-term (28 days) administra tion of MK-801 at three dosages neither abolished behavioral kindled s eizures nor significantly altered generalized seizure thresholds. Howe ver the after discharge duration and postictal spikes were significant ly reduced in rats treated with MK-801 at doses of 0.5 and 1.0 mg/kg, while no significant alterations were observed in rats treated with sa line or MK-801 at a dose of 2.0 mg/kg. Acute effects of MK-801 suggest ed that NMDA receptors were involved in the maintenance of kindling. O n the other hand, long-term treatments with MK-801 remained to show su ch an unequivocal effect. (C) 1997 Elsevier Science B.V.