Exposure to Predator Stress in Gestational Period Potentiates Pilocarpine- induced Epileptic Behaviors in offspring of rat

Introduction: Gestational stress can lead to cerebral functional disorders, such as epilepsy, probably due to the disturbance in the cerebral maturation and causing abnormal neuronal correlations. In the present study, effect of gestational Predator Stress on the neonatal epileptic behaviors was investigated in rats. Methods: Female rats (200 ± 20 g) were divided into two groups; intact pregnant rats (control group) and stressed pregnant rats (stressed group). In the stressed group, on gestational days 15, 16, and 17, caged rats were exposed to the cage of a cat for 2 h, once a day. On postnatal day 25, pilocarpine (150 mg/kg s.c.) was injected to pups of both groups, to induce seizure. Then, epileptic behaviors of each pup was observed and recorded. Results: Mean duration of onset of the first neonatal epileptic behavior of the control group was 5.35 ± 0.57 minutes which was decreased to 3.18±0.24 minutes in the stress group. The mean duration of tonic-clonic attacks was significantly increased from 0.53 ± 0.1 minute in the control group to 16±3.8 minutes in the stressed group. Moreover, mortality rates during attacks and the level of corticosterone hormone in both mothers and pups showed a significant increase in the stressed group in comparison to the control. Conclusion: Gestational stress can enhance epileptic behaviors in the offspring of rats. Further investigation is required to clarify the underlying mechanism.