Sensorineural deafness in adults is primarily due to the permanent loss of sensory hair cells in the inner ear. In this regard, mammals differ from lower vertebrates, which can regenerate sensory hair cells from adjacent supporting cells after injury. It is not known whether this difference arises from a lack of sensory developmental capacity in mammalian support cells, or from a lack of some endogenous stimulus in mammals to provoke regeneration after otic injury. Experiments described in this proposal will mark embryonic sensory and support cell precursors with a fluorescent transgene. These precursors will be purified from embryos using fluorescence activated cell sorting (FACS) and differentiated in vitro, using a recently developed culture system. This system will also be used to isolate and differentiate post-mitotic support cells from embryos and from post-natal animals. From these experiments, it will be determined whether post-mitotic mammalian support cells are able to generate sensory hair cells, and if so, how long in development this capacity persists.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32DC005282-03
Application #
6731043
Study Section
Communication Disorders Review Committee (CDRC)
Program Officer
Sklare, Dan
Project Start
2002-09-01
Project End
2005-02-15
Budget Start
2004-02-16
Budget End
2005-02-15
Support Year
3
Fiscal Year
2004
Total Cost
$48,928
Indirect Cost
Name
House Ear Institute
Department
Type
DUNS #
062076989
City
Los Angeles
State
CA
Country
United States
Zip Code
90057
Doetzlhofer, Angelika; White, Patricia M; Johnson, Jane E et al. (2004) In vitro growth and differentiation of mammalian sensory hair cell progenitors: a requirement for EGF and periotic mesenchyme. Dev Biol 272:432-47