Transneuronal cell atrophy in the congenitally deaf white cat

Deaf white cats with congenitally determined lesions of the organ of Corti were found to have transneuronal degeneration in the form of reduced cell size in the ventral cochlear nucleus and the superior olivary complex. A young deaf white cat with a normal spiral ganglion cell population showed no evidence of acoustic nerve fiber or ending loss despite the presence of atrophied cells in the ventrical cochlear nucleus. Spiral ganglion cell depopulation as found in an adult deaf white cat was evident only in the lower cochlear turns. Graphic reconstructions of the cochleas showed that deaf white cats fell within the normal range of cochlear length and spiral development. A non‐deaf white cat with overdeveloped convolutions of the lateral superior olivary nucleus had the most extensively coiled cochlea of the cats examined.