How can we detect hearing loss in newborn babies?
In our laboratory, based on knowledge of mechanical engineering and auditory mechanics, we would like to contribute to the area of human health by developing unique and effective diagnostic systems. Hearing disorders are reported to occur in about 1-2 out of every 1,000 neonates. Early diagnosis and treatment of such disorders in neonates is highly effective for realization of linguistic competence and intellectual development. Current procedures used for hearing screening programs include otoacoustic emissions (OAEs) and automated auditory brainstem response (ABR). Their diagnostic sensitivities have been reported to be high. Unfortunately, however, it is impossible to diagnose the type of hearing loss such as conductive hearing loss and sensorineural hearing loss using these methods. Therefore, we are focusing on middle ear dynamics and are attempting to develop a non-invasive diagnostic system for such diseases based on the techniques of acoustical engineering. Furthermore, we are focused on applying this system to neonates for early detection of hearing dysfunction.
The motor protein hidden in your inner ear
As many as 12,000 sensory cells called outer hair cells (OHCs) exist in the mammalian inner ear. There are three rows of such cells, and they amplify the hearing sensitivity by several tens of thousands of times by moving in synchronicity with the sound delivered in the inner ear. The origin of this OHC motility is believed to be a motor protein expressed in the plasma membrane of the OHCs. This motor protein has a diameter of one-thousandth of a hair width and is thought to transform its own size. In the laboratory, we are attempting to elucidate this transformation mechanism and to develop a new technology for manipulating this motor protein.