October 20, 2022
It is estimated that over 3.5 million Canadians – roughly 10% of the population – are either culturally Deaf or hard of hearing. Despite this prevalence, our understanding of key aspects of hearing loss have remained a mystery… until now. In our inner ear we have a protein called the transmembrane channel-like protein 1 (TMC1) complex. While scientists have known this TMC1 complex plays an important role in our hearing, its exact purpose wasn’t clear.
To make this incredible discovery, researchers at Oregon Health and Science University (OHSU) in Portland had to recruit some help. Specifically, they first needed to collect 60 million roundworms. The roundworms were essential because humans only have a tiny amount of TMC1, and we don’t have enough to spare. Roundworms use a very similar protein complex to sense touch, so the researchers were able to use them as a source for the study.
As a quick refresher, when noise enters our ears, the soundwaves strike the eardrum, which in turn wiggles the tiny bones of the inner ear, which strike the cochlear, then brush tiny hair cells called stereocilia. OHSU’s researchers have now been able to show that TMC1 facilitates hearing by acting as a tension-sensitive channel, and this channel opens or closes depending on the movement of the stereocilia. When the TCM1 complex channels open and close, they send electrical signals to the brain via the auditory nerve. The brain then interprets those signals as sound.
This new understanding of how the TCM1 complex channels work, and the role they play in our hearing, has the potential to improve the way people with hearing loss are supported. Where appropriate, this new discovery could even lead to changes in the way hearing differences are medically treated in the future, and how future hearing loss is prevented.
Source: Science Alert
Read more: https://www.sciencealert.com/finally-scientists-have-figured-out-a-key-molecular-mechanism-behind-human-hearing