EN
Changes in nonconvulsive spontaneous epileptic activity- Spike-Wave Discharges (SWD) - induced by repeated intraperitoneal (i.P.) administration of crystaline panicillin (CP) at subconvulsive doses were evaluated in imp-DAK rats.Three groups received tan daily i.p.injections of PC at doses of 750.000, 500.000 and 250.000 IU/kg b.w..For comparison, another classic convulsant, penetylenetrazol (PTZ) was applied in the same way to another group.PTZ was also given in CNS excitability.Repeated PC injections resulted in a progressive increase in the basal level of the spontaneous SWD activity and in increase in the SWD response to PC, which was statistically significant in the case of the dose 750.000 IU/kg b.w..Moreover, in all rats given PC the response to PTZ (increase in SWD activity) was reduced.The results obtained in this and previous experiment suggest that in the rat CNS develop which prevent to convulsive effect of Pc but promote the occurence of the spontaneous nonconvulsive SWD activity.