ABSTRACT
Having described a feline model of congenital deafness that implicates the olivocochlear (OC) system as an etiological factor (Walsh et al., 1998a; b), we recently turned our attention to the search for a murine model that will support experiments designed to further test the basic hypothesis that abnormalities of the OC system contribute to the auditory pathophysiology observed in congenital deafness, and support investigations designed to determine the molecular and genetic basis of congenital deafness in general. To that end, we have screened several strains of mice in an effort to identify appropriate murine equivalents of the condition that we refer to as Deefferentation Deafness Syndrome (DDS). The signs of DDS include general loss of acoustic sensitivity, response recruitment, and diminished frequency-resolving power. However, the two most important provisions are that sensory cells retain their morphological integrity, and passive aspects of transduction operate normally in affected individuals. All physiological indices point to a defect in the cochlear amplifier, and outer hair cells (OHCs) by association, as the source of an enduring pathophysiological state following neonatal deefferentation.
