@article{f3c1f653380a4c3cba231d256f6f4148,
title = "Hypothalamic remodeling of thyroid hormone signaling during hibernation in the arctic ground squirrel",
abstract = "Hibernation involves prolonged intervals of profound metabolic suppression periodically interrupted by brief arousals to euthermy, the function of which is unknown. Annual cycles in mammals are timed by a photoperiodically-regulated thyroid-hormone-dependent mechanism in hypothalamic tanycytes, driven by thyrotropin (TSH) in the pars tuberalis (PT), which regulates local TH-converting deiodinases and triggers remodeling of neuroendocrine pathways. We demonstrate that over the course of hibernation in continuous darkness, arctic ground squirrels (Urocitellus parryii) up-regulate the retrograde TSH/Deiodinase/TH pathway, remodel hypothalamic tanycytes, and activate the reproductive axis. Forcing the premature termination of hibernation by warming animals induced hypothalamic deiodinase expression and the accumulation of secretory granules in PT thyrotrophs and pituitary gonadotrophs, but did not further activate the reproductive axis. We suggest that periodic arousals may allow for the transient activation of hypothalamic thyroid hormone signaling, cellular remodeling, and re-programming of brain circuits in preparation for the short Arctic summer.",
author = "Chmura, {Helen E.} and Cassandra Duncan and Ben Saer and Moore, {Jeanette T.} and Barnes, {Brian M.} and {Loren Buck}, C. and Christian, {Helen C.} and Loudon, {Andrew S.I.} and Williams, {Cory T.}",
note = "Funding Information: Funding was provided by the National Science Foundation to C.T.W. and C.L.B. (IOS-1558056) and B.M.B. (IOS- 1558160), the Human Frontiers Science Program Award to A.S.L. (RGP0030/2015), and the Biotechnology and Biological Sciences Research Council UK to A.S.L. (BB/K003119/1). H.E.C. was supported by a University of Alaska Centennial Postdoctoral Fellowship and C.D. received fellowship support through an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health (NIH: P20GM103395). Devin Johnson and staff at the BiRD animal facility at University of Alaska Fairbanks assisted with animal care. Lynn Scott prepared tissues for EM. Danielle Dillon conducted hormone analyses. Aubrey Funck and Elise Adams conducted gonad histology. Meret Buetler, Kyle Callegari, Maddi Michaud, and Sara Sheffer assisted with scoring of immunohistochemistry and EM images. Sara Wilbur helped capture animals in the field. Shona Wood provided useful feedback during early stages of study design. This work was conducted using equipment provided by the University of Manchester Core Histology Facility and Northern Arizona University Histology Facility. Funding Information: Funding was provided by the National Science Foundation to C.T.W. and C.L.B. (IOS-1558056) and B.M.B. (IOS- 1558160), the Human Frontiers Science Program Award to A.S.L. (RGP0030/2015), and the Biotechnology and Biological Sciences Research Council UK to A.S.L. (BB/K003119/1). H.E.C. was supported by a University of Alaska Centennial Postdoctoral Fellowship and C.D. received fellowship support through an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health (NIH: P20GM103395). Devin Johnson and staff at the BiRD animal facility at University of Alaska Fairbanks assisted with animal care. Lynn Scott prepared tissues for EM. Danielle Dillon conducted hormone analyses. Aubrey Funck and Elise Adams conducted gonad histology. Meret Buetler, Kyle Callegari, Maddi Michaud, and Sara Sheffer assisted with scoring of immunohistochemistry and EM images. Sara Wilbur helped capture animals in the field. Shona Wood provided useful feedback during early stages of study design. This work was conducted using equipment provided by the University of Manchester Core Histology Facility and Northern Arizona University Histology Facility. Publisher Copyright: {\textcopyright} 2022, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.",
year = "2022",
month = dec,
doi = "10.1038/s42003-022-03431-8",
language = "English (US)",
volume = "5",
journal = "Communications Biology",
issn = "2399-3642",
publisher = "Springer Nature",
number = "1",
}