Host: The Japanese Society of Toxicology
Name : The 52nd Annual Meeting of the Japanese Society of Toxicology
Date : July 02, 2025 - July 04, 2025
As known from congenital hypothyroidism, thyroid hormones (THs) are essential for the development of the central nervous system. They play a crucial role in regulating gene expression necessary for neurogenesis, neuronal growth, and the formation of neural circuits. Deficiency in THs can lead to irreversible neurodevelopmental impairments. Therefore, early diagnosis and treatment of congenital hypothyroidism are of paramount importance.In Japan, congenital hypothyroidism has been included in neonatal mass screening since 1979, significantly facilitating the detection of severe cases. However, increasing attention has been directed toward conditions such as subclinical congenital hypothyroidism, resistance to thyroid hormone, and disorders of thyroid hormone transport.Our research group, recognizing these developments, has been investigating the impact of THs on neurodevelopment using various mouse models. Our studies aim to elucidate the underlying mechanisms by analyzing behavioral phenotypes. In this presentation, we report the effects of mild perinatal hypothyroidism on memory and learning abilities, motor coordination, and maternal behavior in adulthood.We found that normalizing TH function after weaning allows for catch-up growth and normalization of neuronal morphology at the optical microscopy level. However, despite these structural recoveries, neurological dysfunctions persist into adulthood. This finding highlights that even mild perinatal hypothyroidism can lead to irreversible neurodevelopmental abnormalities. Such evidence underscores the need to consider the potential risks of environmental chemicals that disrupt perinatal thyroid function.Furthermore, we will discuss recent research findings on the impact of perinatal exposure to perfluoroalkyl substances (PFAS), a group of environmental pollutants of growing social concern, on the TH system.
