Thyroid hormones and brain development

It has long been known that thyroid hormone deficiency, when established prior to the critical period of brain development, produces severe and permanent mental retardation both in humans ( cretinism ) and in experimental animals (see Refs. 6 and 101). Most of the early studies aimed at describing the behavioural, physiolog- 

---

Dussault JH, Ruel J 1987 Thyroid hormones and brain development. Annu Rev Physiol 49 321-334... 

Bernal J, Nunez J (1995) Thyroid hormones and brain development. Eur J Endocrinol 755 390-398. 

Grave, G.D. (1977). Thyroid Hormones and Brain Development. Raven Press, New York, NY. 

Ph. De Nayer and B. Dozin. Thyroid hormones and brain development modulation of the binding activity of the T3 nuclear receptor by chromatin-associated factors. Molec. Physiol. 7 303-310 (1985). 

Thyroid hormone and brain development, Ln Multidisciplinary Approach to Brain Development , C. di Benedetta, R. Balazs,... 

Oppenheimer, J. II., and Schwartz, H. L. (1997). Molecular basis of thyroid hormone-dependent brain development. Endocrine Rev. 18, 462-475. 

Morreale de Escobar G, Ruiz-Marcos A, Esobar del Rey F, Thyroid hormones and the developing brain, in "Congenital Hypothyroidism", Dussault J, Walker P (eds), Marcel Dekker, New York (1983), p 85... 

B.S. Hetzel and B.J. Potter, Iodine deficiency and the role of thyroid hormones in brain development, "Neurobiology of the trace elements," I.E. Dreosti and R.M.Smith eds., Humana Press Publ., New Jersey (1983), pp. 83-133. 

Iodine Deficiency and the Role of Thyroid Hormones in Brain Development, Basil S. Hetzel and Brian J. Potter... 

B.S. Hetzel, and B.G. Potter, Iodine deficiency and the role of thyroid hormones in brain development, in I.E. 

Like steroid hormones, thyroid hormones interact with receptors to alter genomic activity and affect the synthesis of specific proteins during development [25-28], As with testosterone and progesterone, metabolic transformation of thyroxine (T4) is critical to its action [25-28]. Moreover, as with steroid hormones, thyroid hormones alter brain functions in adult life in ways that both resemble and differ from their action during development [25-28]. 

The realization that iodine deficiency in pregnancy has a pronounced effect on fetal, neonatal and childhood brain function has resulted in a large body of knowledge on the effects of thyroid hormone on brain and nervous-system development (see Grave, 1977 DeLong et ai, 1989 Stanbury, 1994 Bemal, 2002). 

An insufficient supply of thyroid hormones to the developing brain of the fetus can result in congenital anomalies and intellectual impairment. Further, even mild ID that does not produce increased concentration of thyrotropin... 

Thyroid hormone is essential for normal development of the human brain (Calvo, 1990 Morreale de Escobar et al. 2000). Numerous factors are involved in controlling the levels of receptor-active thyroid hormone, and disruption of any of these at critical phases of human development can lead to severe and persistent cognitive and motor deficits (Haddow, 1999). 

J. Nunez. Microtubules and brain development the effects of thyroid hormones. Neurochem. Int. 7 959-968 (1985). 

M.A. Haidar, S. Dube and P.K. Sarkar. Thyroid hormone receptors of developing chick brain are predominantly in the neurons. Biochem. Biophys. Res. Commun. 112 221-227 (1983). 

Atterwill, C.K., D.J. Atkinson, I. Bermudez. Effect of thyroid hormone and serum on the development of Na,K-ATPase and associated ion fluxes in cultures from rat brain. Neurosci. 361-373, 1985. 

---