Progress in understanding hereditary deafness

26 January 2005

Scientists at the National Institute on Deafness and Other Communication Disorders (NIDCD) report that they have discovered some key mechanisms underlying how stereocilia - the tiny hair-like projections jutting from the top surface of hair cells - develop to form their characteristic architecture.

Hearing takes place at the level of the inner ear hair cells: the basic sensory elements of hearing. Stereocilia are essential components for the normal hearing process since they convert mechanical energy of sound pressure into electrical signals, which sensory hair cells then direct to the brain. This conversion of sound stimuli into electrical signal, also known as mechanoelectrical transduction, is possible only when stereocilia are organized into bundles with a characteristic staircase-like appearance due to closely positioned rows of stereocilia of increasing heights. Abnormalities of this staircase-like architecture can lead to deafness and balance problems.

NIDCD scientist Dr. Inna Belyantseva and her co-authors reported their findings in the January 16 issue of Nature Cell Biology, Advance Online Publication. The research also was supported by the National Heart, Lung, and Blood Institute, another component of the National Institutes of Health.

Dr James F. Battey, director of NIDCD, said this work provides "important new information about the molecular basis for normal hair cell development and offers promise for future efforts in understanding some forms of hereditary deafness at the molecular and genetic level."