Neurotoxicity and molecular effects of methylmercury

Brain Res Bull. 2001 May 15;55(2):197-203. doi: 10.1016/s0361-9230(01)00458-0.


The neurotoxicity of high levels of methylmercury (MeHg) and the high susceptibility of the developing brain are well established both in humans and experimental animals. Prenatally poisoned children display a range of effects varying from severe cerebral palsy to subtle developmental delays. Still unknown is the lowest dose that impairs neurodevelopment. The primary source of human exposure is the fish. The data obtained so far from epidemiological studies on fish-eating populations are not consistent. A reference dose of 0.1 microg MeHg/kg per day has been established by the U.S. Environmental Protection Agency based on a study on Iraqi children exposed to MeHg in utero. However, these exposures occurred at high level for a limited period of time, and consequently were not typical of lower chronic exposure levels associated with fish consumption. Major obstacles for estimation of a threshold dose for MeHg include the delayed appearance of the neurodevelopmental effects following prenatal exposure and limited knowledge of cellular and molecular processes underlying these neurological changes. In this respect, a strategy which aims at identifying sensitive molecular targets of MeHg at environmentally relevant levels may prove particularly useful to risk assessment. Here some examples of MeHg molecular effects occurring at low doses/concentrations are presented.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Death / drug effects
  • Cell Death / physiology
  • Environmental Exposure / adverse effects*
  • Female
  • Humans
  • Mercury Poisoning, Nervous System / metabolism*
  • Mercury Poisoning, Nervous System / pathology
  • Mercury Poisoning, Nervous System / physiopathology
  • Methylmercury Compounds / toxicity*
  • Nerve Tissue Proteins / drug effects
  • Nerve Tissue Proteins / metabolism
  • Nervous System / drug effects
  • Nervous System / growth & development
  • Nervous System / pathology
  • Neurotoxins / toxicity*
  • Pregnancy
  • Prenatal Exposure Delayed Effects


  • Methylmercury Compounds
  • Nerve Tissue Proteins
  • Neurotoxins