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Prenatal Methylmercury Exposure: Effects on Stress Response During Active Learning


The long-term impact of prenatal methylmercury (MeHg) exposure on the stress response during active learning was investigated. Pregnant rats were gavage fed MeHg (8 mg/kg) on gestational day 15. Ninety-day-old rats born to both MeHg- and saline-treated dams were subjected to an active avoidance test. The active avoidance-experienced rats (AAERs) with prenatal exposure to MeHg showed significant impairment in learning ability and exhibited higher levels of corticosterone than the untreated AAERs. The present findings suggest that the abnormal increase in plasma corticosterone levels could contribute to the poor performance of MeHg-treated AAERs in this learning task.

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This study was supported by grants from MiUR (PRIN-COFIN 2003) and Bari University (“Fondo Ateneo” 2005, 2006). A.M.E. Modafferi was supported by a grant from “Enrico ed Enrica Sovena” Foundation. Co-authors have contributed equally to this study.

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Correspondence to Maria Rosaria Carratù.

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Carratù, M.R., Coluccia, A., Modafferi, A.M.E. et al. Prenatal Methylmercury Exposure: Effects on Stress Response During Active Learning. Bull Environ Contam Toxicol 81, 539–542 (2008).

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  • Methylmercury
  • Active avoidance task
  • Plasma corticosterone
  • Rat