Thyroid Hormone Regulation of Specific mRNAS in the Developing Brain

Thyroid hormones, T3 and T4, have been shown to play significant but poorly understood roles in development and differentiation of rodent and human brain (1–7). In the human, disorders of maternal and fetal thyroid function include maternal and secondary fetal iodine deficiency, maternal hypothyroidism or hyperthyroidism, as well as disorders related to deficient fetal autonomous thyroid hormone secretion, i.e., goiter or sporadic congenital hypothyroidism. These disorders are identifiable causes of mental retardation (4, 8, 9, 10), cerebral palsy (11, 12), and other significant neurological abnormalities (5, 6, 11).