A hearing impairment is the most common sensory disorder in humans. The world health organization, WHO considered the loss of hearing even as a pandemic as a world wide Problem that also has an economic Dimension: in the U.S. Alone each year, 50 billion dollars will be spent to eliminate hearing problems. In Europe, about 71 million people with hearing loss are currently affected. Almost half of them is older that 75 years. However, about one billion people worldwide risk of developing a disease at an early stage of hearing damage. “The listeners do at the part with the head,” said the neuroscientist and hearing expert Ulrich Muller from the Johns Hopkins University, last week at a lecture in the “Flagship Store” of the headphone producer Sennheiser on Berlin’s tauentzienstraße as part of a new lecture series, “SMEs meet research”, organized by the Einstein-Stiftung and the Bundesverband Mittelständische Wirtschaft (BMWV).
A Gene that is involved in half of all congenital hearing disorders
noise is not the only reason for hearing damage. Also, protracted ear infections, viruses, and especially hereditary diseases can lead to hearing loss. “The study of such hereditary diseases helps us to understand how hearing damage is caused,” said Müller. For example, that the Gene “Connexin 26” in the inner ear plays an important role in the conversion of sound into nerve impulses. It is, therefore, “the most frequently with a disease-associated” Gene to humanity: “50 percent of all hereditary cases of hearing loss go back on a change in this one gene.”
The Hearing will be transmitted to the air vibrations of sound through the eardrum to the fluid-filled cochlea of the inner ear, the sensory cells for the perception of sounds. “When you are wrapping the cochlea looks like a piano – the sensory cells for the perception of the high tones are on the one, low on the other end.” Depending on the pitch of the liquid is suppressed in the inner ear to the “keys” of the hearing organs, the so-called hair cells. You put the mechanical signals of the sound into electrical signals that are transmitted to the brain.
15000 hair cells per ear – the need for life-rich
For the hair cells need to be intact. And per ear of a human being is born with only about 15,000 of these sensitive cells. “To die, they are lost forever, people are not able to regenerate,” says Müller. And noise added to the cells, so that 10 percent of all hearing loss due to in adults. “The sound, the one has the day after a rock concert in your ear, is a sign that the Connections of hair cells and nerve cells are disturbed,” said Müller.
in the Meantime, the Knowledge about the Hearing process and the involved cells and genes will lead to new therapeutic approaches in regenerative medicine. Here, it is already possible to grow sensory hair cells in the laboratory and also in animal experiments. However, these processes in the human ear utopia was to imitate “in the Moment”, said Müller. Companies such as “Frequency Therapeutics” try-however, the hair cell Regeneration with drugs stimulate.
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gene therapy deafness Hereditary deaf mice, heals the hear after genre repair
Sascha Karberg
Müller gene therapy success holds promise: The idea is, broken, but still living hair cells introduce genes that have a repair effect. In preclinical studies, the flap very well. Clinical studies are in preparation.
