The human ear is a complex and vital auditory structure made up of three main parts – outer, middle and inner. In the inner portion of the ear, humans possess approximately 15,000 tiny, cochlear hair cells. These hairs are vital in receiving sounds and transforming them into noises for the brain to interpret into recognisable sounds.
Unfortunately, these cells are susceptible to damage. Once destroyed, they do not regenerate, which can lead to permanent hearing loss. A reported one in seven Australians live with some form of hearing loss, with 37 per cent of cases caused by repeated exposure to loud noises1.
37 per cent of hearing loss cases are caused by repeated exposure to loud noise.
With no cure in place at present, researchers and scientists are constantly looking to understand the surrounding molecular mechanisms in these cells.
A study into stereocilia
Of the tiny hair cells mentioned previously, each has their own bundle of tiny structures that increase in height and are connected by thin fibres called tip-links, commonly known as stereocilia. Hearing works when sound waves hit stereocilia, which then opens the mechanotransduction ion channels that allow calcium ions to flow into these cells.
Researchers from both the University of Kentucky and the UK College of Medicine looked further into this calcium flow and the stereocilia. This was done by isolating the inner ear tissues of young rodents and exposing some to drugs that blocked the flow of calcium ions through the mechanotransduction channel, compared to others which broke the tip links on the stereocilia 2.
What was discovered?
Results found that both sets of drugs altered the structure and caused a retraction of the stereocilia. When all drugs were rinsed out of the hair cells, they returned to their normal shape. This shows that the flow of calcium ions controls the structure of the stereocilia and more importantly the specific molecular mechanism that does so.
These results not only provide new insight into this field, they also allow for the opportunity to uncover therapies for stabilising this vital auditory structure which could potentially help in treating those with hearing loss.
With breakthroughs and discoveries shedding light on a subject which affects many Australians, here at Adelaide Digital Hearing Solutions we work to help those living with hearing loss with modern technologies and expert advice. To book a hearing assessment at no cost*, call today on 1800 940 982 or click here.
1Deloitte Access Economics, HCIA Report, THE SOCIAL AND ECONOMIC COST OF HEARING LOSS IN AUSTRALIA. Accessed August 2017
2University of Kentucky, UK Physiologists Discover Molecular Mechanism for Stabilizing Inner Ear Cells, with Implications for Hearing Loss. Accessed August 2017