Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Prenatal Methylmercury Exposure: Effects on Stress Response During Active Learning

Abstract

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.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2

References

  1. Carratù MR, Borracci P, Coluccia A, Giustino A, Renna G, Tomasini MC, Raisi E, Antonelli T, Cuomo V, Mazzoni E, Ferraro L (2006) Acute exposure to methylmercury at two developmental windows: focus on neurobehavioral and neurochemical effects in rat offspring. Neuroscience 141:1619–1629. doi:10.1016/j.neuroscience.2006.05.017

  2. Falluel-Morel A, Sokolowski K, Sisti HM, Zhou X, Shors TJ, Dicicco-Bloom E (2007) Developmental mercury exposure elicits acute hippocampal cell death, reductions in neurogenesis, and severe learning deficits during puberty. J Neurochem 103:1968–1981. doi:10.1111/j.1471-4159.2007.04882.x

  3. Forman LJ (2003) The effect of cannabinoid receptor antagonism with SR141716A on antinociception induced by cocaine and the NMDA receptor antagonist, MK-801. Brain Res Bull 61:153–158. doi:10.1016/S0361-9230(03)00103-5

  4. Gould E, Gross C (2002) Neurogenesis in adult mammals: some progress and problems. J Neurosci 22:619–623

  5. Grady RR, Kitay JI, Spyker JM, Avery DL (1978) Postnatal endocrine dysfunction induced by prenatal methylmercury or cadmium exposure in mice. J Environ Pathol Toxicol 1:187–197

  6. Kabuto M (1986) Acute endocrine effects of a single administration of methylmercury chloride (MMC) in rats. Endocrinol Jpn 33:683–690

  7. Karl T, Pabst R, von Hörsten S (2003) Behavioral phenotyping of mice in pharmacological and toxicological research. Exp Toxicol Pathol 55:69–83. doi:10.1078/0940-2993-00301

  8. Lewandowski TA, Pierce CH, Pingree SD, Hong S, Faustman EM (2002) Methylmercury distribution in the pregnant rat and embryo during early midbrain organogenesis. Teratology 66:235–241. doi:10.1002/tera.10098

  9. Mendola P, Selevan SG, Gutter S, Rice D (2002) Environmental factors associated with a spectrum of neurodevelopmental deficits. Ment Retard Dev Disabil Res Rev 8:188–197. doi:10.1002/mrdd.10033

  10. Council National Research (2000) Toxicological effects of methylmercury. National Academy Press, Washington, DC

  11. Ortega HG, Lopez M, Takaki A, Huang QH, Arimura A, Salvaggio JE (1997) Neuroimmunological effects of exposure to methylmercury forms in the Sprague-Dawley rats. Activation of the hypothalamic-pituitary-adrenal axis and lymphocyte responsiveness. Toxicol Ind Health 13:57–66

  12. Pavlides C, Watanabe Y, McEwen BS (1993) Effects of glucocorticoids on hippocampal long-term potentiation. Hippocampus 3:183–192. doi:10.1002/hipo.450030210

  13. Pavlides C, Watanabe Y, Magarinos AM, McEwen BS (1995) Opposing roles of type I and type II adrenal steroid receptors in hippocampal long-term potentiation. Neuroscience 68:387–394. doi:10.1016/0306-4522(95)00151-8

  14. Rice D, Barone S Jr (2000) Critical periods of vulnerability for the developing nervous system: evidence from humans and animal models. Environ Health Perspect 108:511–533. doi:10.2307/3454543

  15. Salmi P, Samuelsson J, Ahlenius S (1994) A new computer-assisted two-way avoidance conditioning equipment for rats: behavioral and pharmacological validation. J Pharmacol Toxicol Methods 32:155–159. doi:10.1016/1056-8719(94)90069-8

  16. Sapolsky RM (2003) Stress and plasticity in the limbic system. Neurochem Res 28:1735–1742. doi:10.1023/A:1026021307833

  17. Scaccianoce S, Del Bianco P, Caricasole A, Nicoletti F, Catalani A (2003) Relationship between learning, stress and hippocampal brain-derived neurotrophic factor. Neuroscience 121:825–828. doi:10.1016/S0306-4522(03)00514-1

  18. Stark H, Bischof A, Wagner T, Scheich H (2001) Activation of the dopaminergic system of medial prefrontal cortex of gerbils during formation of relevant associations for the avoidance strategy in the shuttle box. Prog Neuro-Psychopharmacol Biol Psychiat 25:409–426. doi:10.1016/S0278-5846(00)00171-8

  19. Wedzony K, Maćkowiak M, Zajaczkowski W, Fijal K, Chocyk A, Czyrak A (2000) WAY 100135, an antagonist of 5-HT1A serotonin receptors, attenuates psychotomimetic effects of MK-801. Neuropsychopharmacology 23:547–559. doi:10.1016/S0893-133X(00)00150-0

Download references

Acknowledgements

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.

Author information

Correspondence to Maria Rosaria Carratù.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

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). https://doi.org/10.1007/s00128-008-9557-8

Download citation

Keywords

  • Methylmercury
  • Active avoidance task
  • Plasma corticosterone
  • Rat