@article{cc6a83e1e1404229bef502af9c58a1f0,
title = "Development of hair cell phenotype and calyx nerve terminals in the neonatal mouse utricle",
abstract = "The vestibular organs of reptiles, birds, and mammals possess Type I and Type II sensory hair cells, which have distinct morphologies, physiology, and innervation. Little is known about how vestibular hair cells adopt a Type I or Type II identity or acquire proper innervation. One distinguishing marker is the transcription factor Sox2, which is expressed in all developing hair cells but persists only in Type II hair cells in maturity. We examined Sox2 expression and formation of afferent nerve terminals in mouse utricles between postnatal days 0 (P0) and P17. Between P3 and P14, many hair cells lost Sox2 immunoreactivity and the density of calyceal afferent nerve terminals (specific to Type I hair cells) increased in all regions of the utricle. At early time points, many calyces enclosed Sox2-labeled hair cells, while some Sox2-negative hair cells within the striola had not yet developed a calyx. These observations indicate that calyx maturation is not temporally correlated with loss of Sox2 expression in Type I hair cells. To determine which type(s) of hair cells are formed postnatally, we fate-mapped neonatal supporting cells by injecting Plp-CreERT2:Rosa26tdTomato mice with tamoxifen at P2 and P3. At P9, tdTomato-positive hair cells were immature and not classifiable by type. At P30, tdTomato-positive hair cells increased 1.8-fold compared to P9, and 91% of tdTomato-labeled hair cells were Type II. Our findings show that most neonatally-derived hair cells become Type II, and many Type I hair cells (formed before P2) downregulate Sox2 and acquire calyces between P0 and P14.",
keywords = "RRID AB_10015251, RRID AB_177520, RRID AB_2286684, RRID AB_2721321, RRID AB_531793, Sox2, afferent, calyx, hair cell, type I, type II, vestibular",
author = "Warchol, {Mark E.} and Roxanna Massoodnia and Remy Pujol and Cox, {Brandon C.} and Stone, {Jennifer S.}",
note = "Funding Information: This work was funded by the National Institutes of Health (R01DC013771 to JSS, R01DC014441 to BCC, and R01DC006283 to MEW), the Office of the Assistant Secretary of Defense for Health Affairs (W81XWH-15-1-0475 to BCC), and a Virginia Merrill Bloedel Traveling Scholar Award to RP. For technical assistance, we thank Irina Omelchenko, Jialin Shang, and Glen MacDonald (University of Washington), Xiao-Chun Jin (Washington University), and Kaley Graves and Michelle Randle (Southern Illinois University School of Medicine). The Core Vision Lab (supported by P30 EY01730) provided technical assistance with preparing TEM sections and access to its JEOL TEM microscope; the authors are grateful to the help they received from Dale Cunningham and Ed Parker at this facility. Funding Information: information Office of the Assistant Secretary of Defense for Health Affairs, Grant/Award Number: W81XWH-15-1-0475; National Institutes of Health, Grant/Award Numbers: R01DC006283, R01DC014441, R01DC013771 This work was funded by the National Institutes of Health (R01DC013771 to JSS, R01DC014441 to BCC, and R01DC006283 to MEW), the Office of the Assistant Secretary of Defense for Health Affairs (W81XWH-15-1-0475 to BCC), and a Virginia Merrill Bloedel Traveling Scholar Award to RP. For technical assistance, we thank Irina Omelchenko, Jialin Shang, and Glen MacDonald (University of Washington), Xiao-Chun Jin (Washington University), and Kaley Graves and Michelle Randle (Southern Illinois University School of Medicine). The Core Vision Lab (supported by P30 EY01730) provided technical assistance with preparing TEM sections and access to its JEOL TEM microscope; the authors are grateful to the help they received from Dale Cunningham and Ed Parker at this facility. Publisher Copyright: {\textcopyright} 2019 Wiley Periodicals, Inc.",
year = "2019",
month = aug,
day = "1",
doi = "10.1002/cne.24658",
language = "English",
volume = "527",
pages = "1913--1928",
journal = "Journal of Comparative Neurology",
issn = "0021-9967",
number = "11",
}