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Updated: May 27, 2026
04:14
In vivo Characterization of Endocrine Disrupting Chemical Effects via Thyroid Hormone Action Indicator Mouse
Published on: October 6, 2023
Developmental thyroid hormone disruption: prevalence, environmental contaminants and neurodevelopmental consequences
Mary E Gilbert1, Joanne Rovet, Zupei Chen
1Toxicity Assessment Division (MD-B105-05), US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA. gilbert.mary@epa.gov
Neurotoxicology
|December 6, 2011
Summary
Environmental contaminants can disrupt thyroid hormones (TH), impacting brain development. Research highlights the neurological effects of low-level TH disruptions from factors like iodine deficiency and pollutants.
Area of Science:
- Neurotoxicology
- Endocrinology
- Developmental Neuroscience
Background:
- Thyroid hormones (TH) are crucial for normal growth, development, and particularly brain development.
- Environmental agents can cause marginal reductions in circulating TH, with less known about the effects of modest disruptions compared to severe hypothyroidism.
- Understanding the impact of low-level TH disruptions from environmental contaminants on neurodevelopment is critical.
Purpose of the Study:
- To review the role of TH in brain development and the neurological consequences of thyroid axis disruption.
- To discuss the impact of environmental contaminants on TH signaling and brain development.
- To summarize findings on iodine deficiency and its neurological outcomes, as well as the effects of pollutants like PCBs and PBDEs.
Main Methods:
- Synopsis of presentations from the 13th International Neurotoxicology Association meeting.
- Review of human and animal data on neurological sequelae of thyroid axis disruption.
- Examination of molecular targets of TH signaling affected by persistent organic pollutants.
Main Results:
- Iodine deficiency remains a cause of mental retardation, though iodization programs show efficacy.
- Prenatal TH insufficiency, even in children with initially normal thyroid function, can lead to subtle cognitive impairments and brain imaging abnormalities.
- Environmental contaminants like PCBs and PBDEs disrupt TH signaling at the receptor level, potentially contributing to negative impacts on brain function.
Conclusions:
- Epidemiological, preclinical, and animal research confirms the critical role of TH in brain development.
- Modest perturbations of the thyroid axis by environmental contaminants can lead to neurophysiological, behavioral, structural, and molecular alterations.
- Further research is needed to fully understand the risks associated with environmental contaminants that affect the thyroid axis.
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