Histo-physiological relationships in the deaf white cat auditory system.

An investigation is underway in deaf white cats in order to clear up some problems about the timing of cochlear degeneration, the relationships between physiological and histological findings, and the consequential state of central auditory pathways. The first results reported here show that degeneration of sensory structures was much more advanced than physiological results lead us to believe. The possibility of direct fibre stimulation is discussed. Although degeneration of nervous structures was delayed compared with sensory ones, some early abnormalities in myelination were found. In the adult, completely deaf for years, the electrical stimulation of cochlear nuclei evoked normal-looking field responses at the cortical level. Thus some degree of auditory pathway functional integrity appeared even long after they were disconnected from receptors.