遺伝性難聴の病態マウスモデルの聴覚機能解析

内耳のイオン輸送

抄録

The hearing organ is a sensory apparatus that converts the mechanical stimulation of sound into electrical energy in the cochlea, and then into a neural code in the central auditory pathway. Electrical phenomena in the cochlea include the endocochlear potential (EP), receptor potential of the sensory hair cells, outer hair cell motility, and neurotransmission, all of which involve the maintenance of the intra-and extracellular chemical and electrical environment. Namely, the fundamental and substantial cellular responses of the cochlear cells are based upon an ion transport system responsible for the electrochemical properties, resulting in the efficient energy-yielding processes of acoustic transduction. I focus on functional, molecular biological, and genetic analyses of carrier transporters, ion channels and receptors localized in the cochlea, mainly from the viewpoint of my own works, to clarify the cellular and molecular bases of pathophysiological events and responsible genes for deafness, with the hope that this will in the future contribute to the screening, diagnosis, treatment and prevention of deafness. Tremendous progress in auditory research has been carried out by approaching the genetic basis of deafness. An increasing amount of hereditary deafness is found to be caused by defects of the carrier transporters, ion channels and receptors in the cochlea. Clarifying the physiology, and the structural and molecular framework of the ion transport systems encoded by deafness genes and resolving the underlying mechanisms of deafness could make it possible to develop fundamentally new methods of diagnosis, therapy, and prevention for millions of patients suffering from unknown origins of deafness.