PM347. Postnatal exposure to valproic acid in postnatal day 2–4 rats shows deficit of social interaction

s | 27 Results: Social defeat stress as juveniles, even with 1-day exposure, induced robust and persistent deficits of social behaviors in relation to the unfamiliar ICR mouse, compared with the responses of mice exposed to the stress as adults. The stress did not affect anxiety-like behaviors during spontaneous locomotor activity in a novel environment and performance on the elevated plus-maze or marble-burying test. Additionally, the mice exposed to the stress as juveniles showed the increased serum corticosterone levels and suppressed neurogenesis in the subgranular zone of the dentate gyrus. The persistent deficits of social behaviors and suppression of neurogenesis were prevented by administration of mifepristone prior to the stress. Conclusion: Deficits of social behaviors induced by social defeat stress as juveniles are more persistent than when exposure occurs as adults. The deficits are associated with suppression of neurogenesis in the hippocampus via activation of glucocorticoid receptors. PM347 Postnatal exposure to valproic acid in postnatal day 2–4 rats shows deficit of social interaction Hee Jae Lee1, Tamanna Jahan Mony1, Wanjoo Chun1, Sung Soo Kim1, Emanuel DiCicco-Bloom2,3 1Department of Pharmacology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, Republic of Korea 2Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey 3Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers, the State of New Jersey, New Brunswick,