Physiologists discover molecular mechanism for stabilizing inner ear cells, with implications for hearing loss

April 18, 2017 by Elizabeth Adams, University of Kentucky

Mechanosensory hair cells in the inner ear pick up the softest sounds, such as whispers and distant noises.

Unlike other cells in the , these are fragile and finite. At birth, the contains approximately 15,000 of these cells. They do not regenerate or divide and, therefore are susceptible to permanent damage from exposure to loud sounds. Scientists believe understanding the molecular mechanisms that maintain the structure of these cells throughout the lifespan can provide insight into the fundamental causes of hearing loss and deafness.

University of Kentucky physiologists Catalina Vélez-Ortega, Gregory Frolenkov and their collaborators in the UK College of Medicine have discovered a necessary for stabilizing stereocilia, the "hairs" of the sensory cells of the inner ear. Stereocilia are nanoscale structures grouped together in staircase-like rows and interconnected by extracellular filaments. Hearing happens when sound vibrations deflect stereocilia, tension the extracellular filaments and open mechanotransduction ion channels allowing calcium and other ions to enter the hair cell.

Frolenkov's team discovered that blockage of these channels cause the stereocilia to retract and that this retraction depends on the through these channels. UK researchers uncovered the mechanism maintaining the remarkable staircase-like architecture of the stereocilia. This contribution provides new insight into the molecular mechanisms that facilitate the detection of sound within the inner ear, with opportunities to explore molecular therapies to maintain the stereocilia structure.

This research will appear in an upcoming issue of eLife.

Explore further: Towards a better understanding of inherited hearing loss

More information: A Catalina Vélez-Ortega et al. Mechanotransduction current is essential for stability of the transducing stereocilia in mammalian auditory hair cells, eLife (2017). DOI: 10.7554/eLife.24661

Related Stories

Towards a better understanding of inherited hearing loss

October 15, 2013
A team of researchers led by Dr. Michel Cayouette at the IRCM made an important discovery, published online yesterday by the scientific journal Developmental Cell, that could better explain some inherited forms of hearing ...

Researchers discover two-step mechanism of inner ear tip link regrowth

June 11, 2013
A team of NIH-supported researchers is the first to show, in mice, an unexpected two-step process that happens during the growth and regeneration of inner ear tip links. Tip links are extracellular tethers that link stereocilia, ...

New findings on the workings of the inner ear

October 2, 2012
The sensory cells of the inner ear have tiny hairs called stereocilia that play a critical part in hearing. It has long been known that these stereocilia move sideways back and forth in a wave-like motion when stimulated ...

Protein movement of hair bundles in the inner ear may preserve hearing for life

November 6, 2015
Hearing is made possible when hair bundles protruding from the tops of hair cells capture the energy of sound waves, converting them into electrical signals that stimulate the auditory nerve to the brain. These hair bundles ...

Study finds new role for protein in hearing

August 15, 2011
University of Iowa scientists have discovered a new role for a protein that is mutated in Usher syndrome, one of the most common forms of deaf-blindness in humans. The findings, which were published Aug. 8 in Nature Neuroscience, ...

Recommended for you

Eating at night, sleeping by day swiftly alters key blood proteins

May 21, 2018
Staying awake all night and sleeping all day for just a few days can disrupt levels and time of day patterns of more than 100 proteins in the blood, including those that influence blood sugar, energy metabolism, and immune ...

Deep space radiation treatment reboots brain's immune system

May 21, 2018
Planning a trip to Mars? You'll want to remember your anti-radiation pills.

Receptor proteins that respond to nicotine may help fat cells burn energy

May 21, 2018
The same proteins that moderate nicotine dependence in the brain may be involved in regulating metabolism by acting directly on certain types of fat cells, new research from the University of Michigan Life Sciences Institute ...

Atomic-level study reveals why rare disorder causes sudden paralysis

May 21, 2018
A rare genetic disorder in which people are suddenly overcome with profound muscle weakness is caused by a hole in a membrane protein that allows sodium ions to leak across cell membranes, researchers at the University of ...

New era for blood transfusions through genome sequencing

May 18, 2018
Most people are familiar with A, B, AB and O blood types, but there are hundreds of additional blood group "antigens" on red blood cells—substances that can trigger the body's immune response—that differ from person to ...

Robots grow mini-organs from human stem cells

May 17, 2018
An automated system that uses robots has been designed to rapidly produce human mini-organs derived from stem cells. Researchers at the University of Washington School of Medicine in Seattle developed the new system.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.