“Based on our findings we advise pregnant people to limit their exposure to methylmercury by following Canadian guidelines for fish consumption,” -Dr. Jing WangA study co-led by Dr. Jing Wang and Dr. Laurie Chan is the first to show that exposing pregnant mice to low doses of methylmercury causes autism-like behaviors in their offspring.
Methylmercury is an environmental toxin found in fish. When methylmercury is consumed by pregnant individuals it can affect the fetus’s developing brain. This is why Canadian guidelines recommend pregnant people limit their consumption of certain fish.
While low levels of prenatal methylmercury have been associated with autism in observational studies, this study published in iScience is the first to show how methylmercury may be contributing to autism onset in a rodent model.
The research team gave pregnant mice 0.2ppm of methylmercury per day, slightly more than is recommended for pregnant people.
The resulting pups had an overproduction of neurons in their brain. Offspring also showed impaired communication, decreased sociability, and increased repetitive behaviors. These are all key indicators of autism-like behavior in rodent models.
The team also identified the cellular and molecular mechanisms that led to this neuron overproduction, which may inform strategies to reverse the effects of prenatal methylmercury exposure.
“Based on our findings we advise pregnant people to limit their exposure to methylmercury by following Canadian guidelines for fish consumption,” said Dr. Jing Wang, senior scientist at The Ottawa Hospital and associate professor at the University of Ottawa.
Authors: Allison Loan, Joseph Wai-Hin Leung, David P. Cook, Chelsea Ko, Barbara C. Vanderhyden, Jing Wang, Hing Man Chan.
Core Resources: StemCore Laboratories, uOttawa Animal Behavior Core
Funding: This research was supported by the Natural Sciences and Engineering Research Council of Canada and Canada Research Chair. All research at The Ottawa Hospital is also enabled by generous donors to The Ottawa Hospital Foundation.
The Ottawa Hospital is a leading academic health, research and learning hospital proudly affiliated with the University of Ottawa and supported by The Ottawa Hospital Foundation.
