Growth hormone helps repair the zebrafish ear

September 2, 2011

Loud noise, especially repeated loud noise, is known to cause irreversible damage to the hair cells inside the cochlea and eventually lead to deafness. In mammals this is irreversible, however both birds and fish are able to re-grow the damaged hair cells and restore hearing. New research published in BioMed Central's open access journal BMC Neuroscience shows that growth hormone is involved in this regeneration in zebrafish.

Researchers from Western Kentucky University and the University of Louisville worked together to see which genes were switched on or off after and found distinct patterns of gene expression. Two days after noise injury, cells were busy dividing to repair and replace the damaged hair cells. This repair was associated with an alteration in the regulation of 839 genes and many of the involved were the same as those involved in cancer. This included a massive 64 fold increase in the transcription of growth hormone.

MHC I ZE (a gene involved in regulating immune responses) is down-regulated. But, since a strong inflammatory response to tissue damage can interfere with wound healing, it is probably a good idea to locally inhibit the immune response while repairing injury. Four days after trauma, these levels had begun to return to normal.

Dr. Michael Smith commented, "Injecting growth hormone into zebrafish stimulated cell proliferation in their inner ears, especially cells of the utricle, a vestibular organ involved in balance. There are many homologs between zebrafish and and we are beginning to work on the function of these genes within the ear. Understanding how fish are able to repair their may eventually help us to understand ear injury in people and provide treatments for hair cell loss."

Related Stories

Recommended for you

The current state of psychobiotics

October 25, 2016

Now that we know that gut bacteria can speak to the brain—in ways that affect our mood, our appetite, and even our circadian rhythms—the next challenge for scientists is to control this communication. The science of psychobiotics, ...

Can a brain-computer interface convert your thoughts to text?

October 25, 2016

Ever wonder what it would be like if a device could decode your thoughts into actual speech or written words? While this might enhance the capabilities of already existing speech interfaces with devices, it could be a potential ...

How even our brains get 'slacker' as we age

October 24, 2016

New research from Newcastle University, UK, in collaboration with the Federal University of Rio de Janeiro, investigated the way the human brain folds and how this 'cortical folding' changes with age.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.