Thyroid Hormone Metabolism


Book Description




Iodine and the Brain


Book Description

This volume contains the proceedings of a conference held at the National Institutes of Health in Bethesda on March 21-23. 1988. jointly sponsored by the International Council for Control of Iodine Deficiency Disorders (ICCIDD) and the Fogarty International Center of the National Institutes of Health. Several themes converged to make this meeting timely. The first is an increasing awareness of iodine deficiency disorders as a world-wide problem of public health and a preventable cause of mental deficiency. and as a subject of scientific effort. Increased interest in these problems owes a great deal to accessibility to remote and under developed areas of the world where iodine deficiency persists. As with any subject. greater scrutiny yields unexpected complexity and interest. It is true that provision of iodine. typically as iodized salt, is the necessary and sufficient preventative for iodine deficiency disorders. without including endemic cretinism. This provision is a governmental, economic and social problem. Apart from this, however, the scientific and medical problem of iodine deficiency and its effect on brain development and function is one of great interest and importance for developmental neurology and psychology. Even though the specific preventative agent is known, we do not totally understand the neurobiological questions raised.







Thyroid Hormone Disruption and Neurodevelopment


Book Description

Thyroid hormone plays an important role in development and functional maintenance in the central nervous system. Deficiency of thyroid hormone during fetal and early postnatal life induces abnormal development known as cretinism in humans. However, the molecular mechanism of thyroid hormone action has not yet been fully understood. Thyroid hormone action in the brain may be disrupted under various pathological conditions. In addition, environmental factors including endocrine-disrupting chemicals and bacterial endotoxins may disrupt thyroid hormone action in brain, causing abnormal brain development and functional disruption. This is a first book to comprehensively describe the effect of thyroid hormone disruption in the central nervous system. The first section deals with the disruption of thyroid hormone action at the molecular level. First the authors provide a summary of the possible molecular mechanisms of thyroid hormone action in the brain, then they discuss several factors that may disrupt thyroid hormone action. In the second section, animal models to study thyroid hormone action will be introduced. An interesting character of thyroid hormone deficiency is that, without thyroid hormone, the thyroid hormone receptor may act as a “repressor” of gene expression, causing more severe consequence than those of thyroid hormone receptor knockout animals. Thus, several different kind of animal models may be used to clarify the role of thyroid hormone and its receptor in the brain. In the third section, human studies on thyroid disease and neurodevelopment will be introduced. Although endemic cretinism induced by iodine deficiency and sporadic cretinism by various thyroid mutation are well known, the pathophysiological mechanisms that create each abnormal phenotype are not fully understood. ​










Thyroid Hormone in Brain and Brain Cells


Book Description

Thyroid hormone signaling has been known for a long time to be required for proper neurodevelopment and the maintenance of cognitive functions in the adult brain. As thyroid hormone excess or deficiency is usually well handled by clinicians, research dedicated to the neural function of thyroid hormone, have not been a priority within the field. This is changing mainly for two reasons. First, new genetic diseases have been discovered, altering thyroid hormone signaling in brain (THRA, MCT8, SBP2), with neurodevelopmental consequences which are currently incurable. Second, there is a growing concern that exposition of the general population to environmental chemicals able to interfere with thyroid hormone signaling compromises children neurodevelopment or induces central disorders in adults. Finally thyroid hormone is acting directly on gene transcription, by binding nuclear receptors, and therefore is an interesting entry point to identify genetic programs controlling brain development and function. Reaching a broad understanding of the multiple processes involving thyroid hormone in brain is a tremendous task which will necessitate a multidisciplinary approach: animal genetics, molecular biology, brain imaging, developmental biology, genomics, etc... This topic will be the occasion to combine recent contributions in the field and to identify priorities for future investigations. Due to devastating consequences of congenital hypothyroidism, the neurodevelopmental consequences of altered thyroid hormone signaling have been extensively studied over the years. The discovery of new genetic diseases, the concern about the possible neurotoxicity of environmental thyroid hormone disruptors, recently renewed the interest for an important research field. This Ebook gathers reviews and original data from experts in various disciplines. It provides a broad view of ongoing research and outlines key issues for future investigation.




From Neurons to Neighborhoods


Book Description

How we raise young children is one of today's most highly personalized and sharply politicized issues, in part because each of us can claim some level of "expertise." The debate has intensified as discoveries about our development-in the womb and in the first months and years-have reached the popular media. How can we use our burgeoning knowledge to assure the well-being of all young children, for their own sake as well as for the sake of our nation? Drawing from new findings, this book presents important conclusions about nature-versus-nurture, the impact of being born into a working family, the effect of politics on programs for children, the costs and benefits of intervention, and other issues. The committee issues a series of challenges to decision makers regarding the quality of child care, issues of racial and ethnic diversity, the integration of children's cognitive and emotional development, and more. Authoritative yet accessible, From Neurons to Neighborhoods presents the evidence about "brain wiring" and how kids learn to speak, think, and regulate their behavior. It examines the effect of the climate-family, child care, community-within which the child grows.




Losing Our Minds


Book Description

The exponential increases in neurodevelopmental disorders implicate both genetic causes and environmental factors. Flame-retardants, pesticides, plasticizers, and other every-day products contain chemicals shown to affect thyroid hormone signaling, which if disrupted can result in significant impairment to IQ. Across entire populations, such effects spell large-scale social and economic consequences. In this book Barbara Demeneix suggests what can and must be done to halt and reverse this disturbing trend.