Research identifies cell mechanism underlying tinnitus

Posted by pt91 at May 10, 2012 04:25 PM |
Study could pave way for first drug treatments
Research identifies cell mechanism underlying tinnitus

From 'The Descent of Man'. Source: Wikipedia

Researchers in the University of Leicester's Department of Cell Physiology and Pharmacology have identified a cellular mechanism that could underlie the development of tinnitus following exposure to loud noises.

Tinnitus is a sensation of phantom sounds, usually ringing or buzzing, heard in the ears when no external noise is present. It commonly develops after exposure to loud noises (acoustic over-exposure), and scientists have speculated that it results from damage to nerve cells connected to the ears.

Dr Martine Hamann and her team, including PhD student Nadia Pilati, looked at cells in an area of the brain called the dorsal cochlear nucleus - the relay carrying signals from nerve cells in the ear to the parts of the brain that decode and make sense of sounds. Following exposure to loud noises, some of the nerve cells (neurons) in the dorsal cochlear nucleus start to fire erratically, and this uncontrolled activity eventually leads to tinnitus.

The team were also, for the first time, able to link cellular bursting activity to specific potassium channels that help regulate the nerve cell's electrical activity. Ordinarily, these cells only fire regularly and therefore regularly return to a rest state. However, if the potassium channels are not working properly, the cells cannot return to a rest state and instead fire continuously in random bursts, creating the sensation of constant noise when none exists.

Research Councils UK, the Wellcome Trust, GlaxoSmithKline and Deafness Research UK all contributed funding to the work, while further pharmaceutical research is due to take place with Autifony Therapeutics Ltd via a Medical Research Council Case studentship.

Although hearing loss and tinnitus affect around ten percent of the population, there are currently no drugs available to treat or prevent tinnitus.