Balance depends on preserving inner hair cells in the ear

Led by Mathieu Beraneck, researchers at the University of Paris Cité/CNRS and the University of Barcelona explored the strength of the relationship between a type of inner hair cell in the ear and balance. Their work is published in eNeuro. Says Beraneck, "After 200 years of research on this system, still no one has demonstrated the quantity of hair cells necessary for balance, so our study is a first step in answering this long-standing question." 

Using mice, the researchers assessed how sensitive balancing and orienting abilities are to the loss of a subtype of inner hair cells. "Normal" functioning of organs that enable balance required 80% of these hair cells, whereas the presence of 50% of these hair cells supported minimal functioning of these organs. 

Speaking on treatment implications, Beraneck emphasizes that this work suggests it may be possible to improve balance by restoring this hair cell population in the inner ear through interventions such as gene therapy. "A conservative target should be to restore at least 50% of inner hair cells. What remains to be seen is the specific role of another type of hair cell that we did not examine, but, in our hands, it looks like the part of the system we investigated is very dependent on the subtype we assessed and targeted."