title: New hair cells arise from supporting cell conversion in the acoustically damaged chick inner ear.
abstract: Supporting cell mitosis contributes significantly to hair cell regeneration in the acoustically damaged bird inner ear. Yet there may be another mechanism of hair cell replacement: supporting cell conversion. This study used cytosine arabinoside (Ara-C), an inhibitor of DNA synthesis, to better determine whether supporting cells could transdifferentiate into hair cells without cell division. Chicks received Ara-C injections after acoustic overstimulation. Scanning microscopic studies of the basilar papillae revealed several unpaired, immature hair cells. To ensure Ara-C's blockage of DNA synthesis, one group of birds received both Ara-C and bromodeoxyuridine (BrdU), while another group had BrdU only. Immunocytochemical analysis of Ara-C/BrdU and BrdU papillae indicated zero and 16 dividing cells, respectively. This difference confirmed that Ara-C blocked DNA synthesis, arresting supporting cell mitosis. These data strongly suggest that supporting cell can convert into hair cells.
authors.affiliation: Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor 48109-0648, USA.
authors.forename: H J
authors.initials: HJ
authors.lastname: Adler
authors.forename: Y
authors.initials: Y
authors.lastname: Raphael
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002645:Chickens; D003561:Cytarabine / Q000494:pharmacology; D004427:Ear Diseases / Q000503:physiopathology*; D007758:Ear, Inner / Q000503:physiopathology*; D006198:Hair Cells, Auditory / Q000502:physiology* / Q000648:ultrastructure; D008938:Mitosis; D009622:Noise
chemical_list: D003561:Cytarabine