What is it about?
Thyroid hormones (THs) play a crucial role in the development and physiological functioning of different body organs especially the brain. Therefore, the objective of this study was to show the histopathological effects of the different thyroid states on some brain regions (cerebrum and cerebellum) and the skeletal features of their newborns during the postnatal development from the 1st to 3rd week. The female white albino rats were allocated into 3 groups as follows: the experimental hypothyroidism group is induced by 0.02% methimazole (MMI) (w/v) in drinking water, while the experimental hyperthyroidism group is performed by exogenous T4 [from 50 to 200g/kg body weight intragastric administration beside adding 0.002% T4 (w/v) to the drinking water] from the gestation day 1 to lactation day 21 and control group which received tap water. As well, both maternal hypo- and hyperthyroidism caused some malformation and developmental defects in the cerebellar and cerebral cortex of their newborns along the duration of the experiment. These degenerative symptoms became more prominent and widely spread at the 3rd postnatal week. Concomitantly, there were some degeneration, deformation and severe growth retardation in neurons of these regions in both treated groups throughout the experimental period. Moreover, the skeletal features of these newborns were accelerated in hyperthyroid group while these maturations were delayed partially in hypothyroid ones during the examined periods. These alterations, on both treated groups, were age and dose dependent. Thus, further studies need to be done to emphasize this concept.
Featured Image
Why is it important?
The experimental work herein will require additional evidence at a molecular level either demonstrating a direct action of the thyroid hormones on the fetal brain or additional evidence supporting the suggestion that the observed effects of maternal hypo- or hyperthyroidism on fetal development are explained by impaired gestation.
Perspectives
whether the adverse effects of maternal hypo- or hyperthyroidism on fetal development are mediated directly by loss of the maternal hormones contribution to the fetus, indirectly by metabolic impairment of gestation, or both. In addition, future attention should be focused on identifying a non-genomic approach because of there is scant evidence and these actions of thyroid hormones (THs) differ across the developmental time and brain region.
Full Professor Ahmed R. G.
Division of Anatomy and Embryology, Zoology department, Faculty of Science, Beni-Suef University, Egypt.
Read the Original
This page is a summary of: Comparative study of the effects of experimentally induced hypothyroidism and hyperthyroidism in some brain regions in albino rats, International Journal of Developmental Neuroscience, April 2010, Wiley,
DOI: 10.1016/j.ijdevneu.2010.04.003.
You can read the full text:
Resources
Contributors
The following have contributed to this page
