Prenatal Pentylenetetrazol exposure alters the susceptibility to convulsive and non-convulsive epilepsy in WAG/Rij offspring

The effects of prenatal treatment with pentylenetetrazol (PTZ) on convulsive and non-convulsive epilepsy were studied in WAG/Rij rats. These rats are genetically prone to absence epilepsy. Pregnant female rats were either repeatedly injected with Pentylenetetrazol (PTZ) (40 mg/kg i.p.) or saline. The offspring was divided into four independent groups that were challenged with PTZ at one of the following postnatal days (PD): 40-th, 70-th, 100-th and 130-th. There was an age-dependent decrease in seizure threshold and in seizure latency. Furthermore, the PTZ pre-treated group had a higher seizure threshold than the control group but this was reversed at PD 70: the control group had a higher seizure threshold at that time. EEG monitoring at the age of 110-140 days showed a lower number of spontaneously occurring spike-wave discharges for the PTZ than for the control group. This demonstrates that prenatal PTZ treatment protects rats against PTZ-induced seizures and spike-wave discharges. In conclusion, it seems that the long-term consequences of prenatal exposure to PTZ demonstrate that functional changes in the central nervous system have taken place. These functional changes have consequences for the susceptibility of different types of epilepsies.