A genetic approach to understanding auditory function

Little is known of the molecular basis of normal auditory function. in cont rast to the visual or olfactory senses, in which reasonable amounts of sens ory tissue can be gathered, the auditory system has proven difficult to acc ess through biochemical routes, mainly because such small amounts of tissue are available for analysis. Key molecules, such as the transduction channe l, may be present in only a few tens of copies per sensory hair cell, compo unding the difficulty. Moreover, fundamental differences in the mechanism o f stimulation and, most importantly, the speed of response of audition comp ared with other senses means that we have no well-understood models to prov ide good candidate molecules for investigation. For these reasons, a geneti c approach is useful for identifying the key components of auditory transdu ction, as it makes no assumptions about the nature or expression level of m olecules essential for hearing. We review here some of the major advances i n our understanding of auditory function resulting from the recent rapid pr ogress in identification of genes involved in deafness.