Abstract

Objective(s): Stress during pregnancy is able to bring extensive effects on neurobehavioral development in offspring. The GABAergic system plays a pivotal role in neuronal excitability, which can be affected by prenatal stress (PS). This study aimed to evaluate impact of the PS on gamma 2 subunit of gamma-aminobutyric acid A (GABAA) receptor gene expression in the hippocampus and seizure induced by pentylenetetrazol (PTZ) in developing rats. Materials and Methods: In this experimental study, female Wistar rats were exposed to restraint stress during gestation and their offspring were studied on postnatal days 14 and 21 (P14 and P21, respectively) for epileptic behaviors and gamma 2 GABAA receptor subunit gene expression. Quantitative real-time PCR was used for evaluating the gamma 2 GABAA receptor subunit gene expression in rat pups. Meanwhile, PTZ was injected into the pups, and seizure behaviors were recorded for 60 min. Results: The results showed that gamma 2 subunit mRNA expression significantly increased in the hippocampus of the stressed pups. The expression level of gamma 2 subunit was higher on P21 compared to that on P14 in both groups. Number of seizures with tonic-clonic features increased in pups of stressed group compared to the control group. Prenatal stress significantly caused an increase in the total score of seizure on P21. Conclusion: The effect of PS on seizure susceptibility is age-specific; the increased gamma 2 subunit level in the hippocampus might be, at least in part, the underlying mechanism for PS-induced augmentation of seizures in immature rats.