@article{22b57fc753ce4496a955a6a16ce1206f,
title = "Magnetic resonance imaging and volumetric analysis: Novel tools to study the effects of thyroid hormone disruption on white matter development",
abstract = "Humans and wildlife are exposed to environmental pollutants that have been shown to interfere with the thyroid hormone system and thus may affect brain development. Our goal was to expose pregnant rats to propylthiouracil (PTU) to measure the effects of a goitrogen on white matter development in offspring using magnetic resonance imaging (MRI) and volumetric analysis. We exposed pregnant Sprague Dawley (SD) rats to 3 or 10. ppm PTU from gestation day 7 (GD7) until postnatal day 25 (P25) to determine the effects on white matter (WM), gray matter (GM), and hippocampus volumes in offspring. We sacrificed offspring at P25 but continued the life of some offspring to P90 to measure persistent effects in adult animals. P25 offspring exposed to 10. ppm PTU displayed lowered levels of triiodothyronine (T3) and thyroxine (T4); cerebral WM, GM, and total brain volumes were significantly lower than the volumes in control animals. P90 adults exposed to 10. ppm PTU displayed normal T3 levels but lowered T4 levels; WM, GM, total brain, and hippocampal volumes were significantly lower than the volumes in control adults. Both P25 and P90 rats exposed to 10. ppm PTU displayed significant reductions in percent WM as well as heterotopias in the corpus callosum. Exposure to 3. ppm PTU did not produce any significant effects. These results suggest that MRI coupled with volumetric analysis is a powerful tool in assessing the effects of thyroid hormone disruption on white matter development and brain structure. This approach holds great promise in assessing neurotoxicity of xenobiotics in humans and wildlife.",
keywords = "Brain, Magnetic resonance imaging, Myelination, Thyroid hormone, White matter",
author = "Powell, {Michael H.} and Nguyen, {Hao Van} and Mary Gilbert and Mansi Parekh and Colon-Perez, {Luis M.} and Mareci, {Thomas H.} and Eric Montie",
note = "Funding Information: The authors thank the staff of the animal facility at the All Children's Hospital in St. Petersburg, Florida at the University of South Florida for their help in animal care, blood collection, brain fixation and removal, and Garrett Astary and William Triplett of the University of Florida for their assistance with MR imaging and data processing. We would also like to thank the following students from the University of South Carolina Beaufort for their help in segmentation of brain structures: Ilton Cubero, Justin LaFrance, Jessica Perrulli, and Kathleen Armstrong. We thank Drs. Karl Jensen and Shonagh O{\textquoteright}Leary-Moore for their comments on an earlier version of this manuscript. MRI data were supported through the National High Magnetic Field Laboratory and obtained at the Advanced Magnetic Resonance Imaging and Spectroscopy Facility in the McKnight Brain Institute of the University of Florida. This study was supported under a Subaward with the University Corporation of Atmospheric Research (UCAR) under Grant No. NA06OAR4310119 (Training Tomorrow's Ecosystem and Public Health Leaders Using Marine Mammals as Sentinels of Oceanic Change) with the National Oceanic and Atmospheric Administration (NOAA), US Department of Commerce. We also acknowledge the partners of this training grant: University of California Davis Wildlife Health Center, The Marine Mammal Center, and Northwest Fisheries Science Center (NWFSC). Additional funding was provided by the National Institute of General Medical Sciences (NIGMS) grant no. P20GM103499 of the National Institute of Health (NIH), and the National Institute of Neurological Diseases and Stroke (NINDS) grant no. R01NS063360 of the NIH. This document has been subjected to review by the National Health and Environmental Effects Research Laboratory and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. ",
year = "2012",
month = oct,
doi = "10.1016/j.neuro.2012.08.008",
language = "English",
volume = "33",
pages = "1322--1329",
journal = "NeuroToxicology",
issn = "0161-813X",
publisher = "Elsevier",
number = "5",
}