Effects of the neurotrophic factors BDNF, NT-3, and FGF2 on dissociated neurons of the cochlear nucleus.

The cochlear nucleus is the first relay station for acoustic information in the auditory pathway and its cellular integrity is affected by hearing loss. Neurotrophic factors, which are known to regulate fundamental processes in the brain, are expressed in the cochlear nucleus and are regulated by the changes in the stimulation. The aim of this study was to evaluate the effect of the neurotrophins Brain derived neurotrophic factor (BDNF) and Neurotrophin 3 (NT-3) and the neurotrophic factor Fibroblast growth factor 2 (FGF2) on primary cultured cells of the mouse cochlear nucleus. No effect on overall cell growth was detected after 8 days in culture by the factors applied. NT-3 had a strong impact on enhancement of neuronal survival, whereas BDNF stimulated neuronal survival and axonal outgrowth. Axonal branching was negatively affected by the administration of BDNF. FGF2 did not show any effect. The results presented represent fundamental research on auditory neurons, but might be one step toward defining novel therapeutic strategies in the future to prevent cochlear nucleus degeneration induced by hearing loss.