|
Notes:
|
Curs 2012-2013
Death of sensory hair cells in the inner ear results in two global health problems that millions of
people around the world suffer: hearing loss and balance disorders. Hair cells convert sound vibrations and
head movements into electrical signals that are conveyed to the brain, and as a result of aging, exposure to
noise, modern drugs or genetic predisposition, hair cells die.
In mammals, the great majority of hair cells are produced during embryogenesis, and hair cells that
are lost after birth are not replaceable. However, in the last decades, researches have shown some model
organisms that retain the ability to regenerate hair cells damaged after embryogenesis, such as Zebrafish
and chicken, providing clues as to the cellular and molecular mechanisms that may block hair cell
regeneration in mammals. This discovery initiated a search for methods to stimulate regeneration or
replacement of hair cells in mammals, a search that, if fruitful, will revolutionize the treatment of hearing
loss and balance disorders.
One aim of my project is to study the role of retinoic acid in adult Zebrafish and in mice, which is a
metabolite of vitamin A known as an essential molecule to activate hair cell regeneration after cells
damaged in Zebrafish embryo. We want to study important genes involved in retinoic acid pathway, such as
Aldh1a3 and RARs genes, to check what their role is in the inner ear of adult Zebrafish and compare result
obtained in the inner ear of mice.
On the other hand, Zebrafish lateral line contains neuromast, which are formed by the same
structure than the inner ear: hair cells surrounded by supporting cells and neurons. The lateral line is a
structure below the skin's surface that makes easier to damage hair cells to study their regeneration. For
that reason, another aim of my project is to study how Sox2 and Atoh1, essential genes during the inner ear
development, change their expression during hair cell regeneration in the lateral line.
In my project, the most important concepts related to Zebrafish world are explained in order to
understand why we have studied this animal and these essential genes. Then, techniques that we used are
explained, with their protocol attached in the annexes. Finally, results of my project are shown, but many
of them were not expected and they would be needed to follow studying. |
