University of Washington Hair Cell Regeneration
Progress
Editor: The University of Washington has long been involved in the
study of auditory hair cells and hair cell regeneration. One interesting
avenue of study has been the ability of birds to regenerate defective
hair cells. The researchers at the University of Washington have
recently published a paper summarizing their work. Here is their press
release. For additional information, please visit http://www.washington.edu
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Scientists have known for years that birds' ears do something human
ears cannot: when hair cells in the avian ear are destroyed, the bird
goes deaf only temporarily. Now, research at the University of
Washington is showing why.
In a paper published in the Oct. 24 issue of the Proceedings of the
National Academy of Sciences, Dr. Edwin W. Rubel, the Bloedel professor
of hearing science, and Research Assistant Professor Jennifer Stone
explain what is known about how the process works in birds. Once that
mechanism is completely traced, the next step will be studies of how
that knowledge might be transferred to mammals, including humans.
"What we detail in this paper is the sequence of events the
cells go through in order to make new hair cells. In most cases, this
involves a support cell that sits near the base of a hair cell,"
Rubel said in a recent interview at the UW Virginia Bloedel Hearing
Research Center and Department of Otolaryngology.
"When the nearby avian hair cell dies, this support cell is
stimulated by some external process to develop into a new hair cell,
just like human skin cells."
The new hair cell then somehow gets linked to the brain and the
nervous system and develops all the same biochemical characteristics the
original hair cell had. This doesn't happen in mammals. Stone said the
discovery of this capability in birds at the UW 12 years ago
contradicted everything then known about neurobiology and hearing. When
hair cells in humans and other warm-blooded vertebrates are killed, the
nearby cells do not start dividing as they did before birth.
Rubel said the key is understanding how the mechanism for the
destruction of a hair cell could be stopped. If researchers can
establish the cascade of steps involved in the cellular death, they
would be able to interrupt the process, and prevent the development of
some forms of deafness before they start.
Stone and Rubel agreed their research would not lead directly to a
cure for human deafness in the near future.
"It's really important to recognize the increased complexity of
the mammalian auditory organ, compared to the birds," Stone said.
"Simply making a hair cell, while it seems like an automatic
process in a chicken, is a much larger task in a human, because of the
complexity of the mammalian auditory system."
The research has opened new paths for significant progress in hearing
protection and conservation directly as a result of the avian hair cell
research. Rubel and Stone said they hope their work attracts more
investigators to the field, in search of more solutions to hearing loss.
"When people ask me if we have cured deafness, I say what we've
done is establish the question. We established the possibility that
other approaches could be used besides hearing aids and cochlear
implants," Rubel said. "These are areas that researchers
weren't even considering before. That's how one establishes a new area
of research and draws more researchers into it, multiplying the progress
dramatically."
Rubel first reported the phenomenon of avian auditory hair cell
regeneration in a Science article 12 years ago.
