Age-related increase of spontaneous aural cholesteatoma in the Mongolian gerbil.

The Mongolian gerbil is the only non-human animal known to spontaneously develop aural cholesteatomas. In this rodent, both the prevalence of spontaneous cholesteatomas and the resultant peripheral auditory evoked potential threshold increases from 6 to 18 months of age. By 24 months, the end of their median life span, other factors begin to affect auditory function. Therefore, the electrocochleographic technique can be efficiently used to nontraumatically trace the development of the cholesteatoma from 6 to 18 months, providing an experimental method for evaluating techniques to prevent or retard the growth of aural cholesteatomas.