Effects of neurotrophins on early auditory neurones in cell culture

DURING the first week of postnatal development, the innervation of the organ of Corti changes from an immature to an adult pattern. Dissociated cell cultures of early postnatal spiral ganglia were used to investigate the effects of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) on maturing auditory neurones. BDNF was the most potent stimulator of neuritogenesis, NT-3 provided the strongest support for neuronal survival, while NGF supported limited neuritogenesis, and only at pharmacological levels. These findings suggest that both BDNF and NT-3 participate in the postnatal maturation of cochlear innervation and that NGF is most probably not involved in this process.