title: Estrogen blockade reduces auditory feedback in CBA mice.
abstract: OBJECTIVE
  To examine the effects of estrogen suppression on age-related changes in distortion product otoacoustic emissions (DPOAEs) and contralateral suppression (CS) of DPOAEs in CBA mice.
  
  
  METHODS
  Young CBA mice received a slow-release shoulder implantation of either tamoxifen or placebo. Serial DPOAEs and CS of DPOAEs were obtained at 3-week intervals over a period of 9 weeks.
  
  
  RESULTS
  Although DPOAEs were maintained over the study interval, CS of DPOAEs decreased significantly with age in the experimental group. No such declines were observed in either the control animals or the untreated male mice.
  
  
  CONCLUSIONS
  Estrogen suppression negatively affects the MOC efferent feedback system.
  
  
  CONCLUSIONS
  Our results support the hypothesis that estrogen plays an important role in the maintenance of auditory integrity. Additionally, our findings raise intriguing questions about auditory effects of hormonal shifts in humans resulting from menopause, hormone supplements such as oral contraceptives, and hormone replacement therapy as well as antiestrogens.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Rochester School of Medicine and Dentistry, 973 East Avenue, Rochester, NY 14607, USA. scott_thompson@urmc.rochester.edu
authors.forename: Scott K
authors.initials: SK
authors.lastname: Thompson
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Zhu
authors.forename: Robert D
authors.initials: RD
authors.lastname: Frisina
mesh_terms: D000375:Aging / Q000187:drug effects*; D000818:Animals; D001307:Auditory Perception / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D004965:Estrogen Antagonists / Q000494:pharmacology*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006311:Hearing Disorders / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D004965:Estrogen Antagonists; D004967:Estrogens; D013629:Tamoxifen