Predator and restraint stress during gestation facilitates pilocarpine-induced seizures in prepubertal rats

Stress during gestation can result in early and long‐term developmental aberrations. This study aimed to assess the impact of prenatal restraint or predator stress on pilocarpine‐induced epileptic behavior. Pregnant rats were exposed to stressors on gestational days 15, 16, and 17. Restraint stress consisted of daily restraint of the dam. During predator stress, caged rats were exposed to a cat in a cage. On postnatal day 25, male pups were injected with pilocarpine and the behavior of each rat was observed. Prenatal stress led to low birth weight and increased blood corticosterone levels. Both stressors significantly potentiated pilocarpine‐induced seizures. Predator‐stressed pups exhibited significantly severe tonic–clonic seizures compared with restraint‐stressed animals. These data emphasize the impact of prenatal stress on fetal growth, and neural and endocrine function. The results also suggest that psychosocial stressors have a greater impact on neural and endocrine function than physical stressors do. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:806–812, 2011.