Prenatal PTZ exposure alters the susceptibility to PTZ-induced and nonconvulsive epilepsy in rats

The effects of prenatal PTZ treatment on convulsive threshold for PTZ and s pontaneously occurring spike-wave discharges (SWD) were studied in WAG/Rij rats. Pregnant females were either repeatedly injected with PTZ (40 mg/kg i .p.) or saline. The offspring were divided into four groups that were chall enged with PTZ at one of the following postnatal days (PD): 40-th, 70-th, 1 00-th and 130-th. The PTZ pre-treated group had a higher PTZ seizure thresh old than the control at Pl) 40, 100 and 130, not at PD 70: than the control group had a higher threshold. Next there was an age-dependent decrease in seizure threshold and latency. EEG monitoring at the age of 110-140 days showed a lower number of SWD for WAG/Rij rats prenatally treated with PTZ than for the control group. These results demonstrate that prenatal PTZ treatment protects rats against PTZ-i nduced seizures and SWD.