Spontaneous regeneration and recovery of hearing function of the central auditory pathway in young rats.

Spontaneous regeneration of the auditory pathway after transection of the ventral cochlear tract of the brain stem to pons was examined in young rats by the anterograde tracing method with wheat germ agglutinin-conjugated horseradish peroxidase. Care was taken to cut the tract as sharply as possible to minimize traumatic injuries. About 59% of the young rats examined showed successful regeneration. Functional recovery of hearing by the regenerated fibers was confirmed by the auditory brain stem response. Thus, the present findings contradict the widely held view that the mammalian central auditory system cannot be restored following damage.