Partial or complete hearing loss – a very common age-related a violation. Most often it occurs in people who during life are constantly exposed to loud sounds. This form of hearing loss is called synaptopathies.
biologists from the United States figured out why it occurs, but decided to focus not on the treatment of existing injuries and preventing them. To do this, the team developed a “chemical headphones” that should reduce the negative effects, while not drowning out audible sounds.
the Authors explain: when the hair cells of the inner ear can perceive the vibrations from the sound waves, they emit a chemical substance called glutamate across the synapse to receptor cells. The latter transmit a signal through the auditory nerves to the brain.
But prolonged exposure to loud sounds cells can produce too much glutamate, which eventually disrupted receptors and, consequently, deteriorating hearing.
In the new work, the researchers found that some of the receptors involved in signal transmission from the hair cells in the nervous, missing a protein called GluA2. And that it plays a key role in the development of synaptopathy.
Tests have shown that glutamate receptors lacking GluA2 protein allow calcium ions to enter the neurons of the inner ear, where they cause damage. So scientists have had a target for new therapies.
the Team developed the drug, selectively blocking receptors lacking GluA2 protein. It turned out a kind of “chemical headphones”, explain the authors.
Tests on mice showed that the drug effectively prevents the passage of calcium through the receptor (and hence disease). The remaining receptors containing GluA2, cope well with their duties on the transfer of the sound signal to the brain. In other words, an experimental drug helps preserve hearing, even if the animal is subjected to a Shuthe Dom.
“We found that if you block the receptors lacking GluA2 protein, or calcium-permeable receptors, it is possible to prevent the damage, and the mouse can hear very well because she still has receptors containing GluA2, which can mediate synaptic transmission, said co-author Professor Stephen green (Steven Green) from the University of Iowa. — Now we have a drug that does not affect the hearing, but prevents its deterioration”.
since the tests were conducted only on laboratory animals, while there is no guarantee that the new drug will help to prevent hearing loss in humans. However, the authors believe that the direction and their discovery will help many patients.
In the future the scientists will not only conduct clinical trials but also considerably to Refine a new medicine. At this stage it is necessary to enter in the cochlea of the ear through surgical intervention. The ultimate goal of researchers is a drug that needs to get into the body or non-invasive with minimal trauma to the tissues.
“Our “chemical headphones” now indicate the direction for [future] studies, but are not yet proven and safe remedy of human hearing, says green. — People should [still] be careful to influence of noise, because we are still unable to restore synapses or to regenerate hair cells”.
On the work done, the team reported in a paper presented in the journal PNAS.
by the Way, earlier “Conduct.Science” talked about how to assess hearing acuity in the eyes, and a new method of treatment of deafness and that hearing loss may be a consequence of Smoking.