NEUROTROPHINS AFFECT SURVIVAL AND NEURITOGENESIS BY ADULT INJURED AUDITORY NEURONS IN-VITRO

This study evaluates the trophic effects of three neurotrophins on traumatized adult auditory neurons in culture, and the presence of these neurotrophins in cochlear nucleus tissue. BDNF and NT-3 promoted survival but very limited neuritogenesis by adult auditory neurons in vitro, while NGF, although without a survival effect, evoked a robust neuritic outgrowth response when combined with BDNF. Messenger RNAs that encode for NGF, BDNF and NT-3 were detected by RT-PCR in RNA extracts from adult cochlear nuclei tissue. Based on these in vitro and in vivo findings, we propose NT-3 as the agent of the peripheral target-derived survival promoting effect and NGF, BDNF, and NT-3 as mediators of trophic influences originating from the central target (i.e. cochlear nucleus).