embryonic rat hippocampal cells were cultured in basal medium with or without addition of the neurotrophin NT-3. After culturing in these extreme conditions, the effects of NT-3 on the neuronal and on the glial components were assessed. Neurons survived even in the absence of NT-3 but failed to reach terminal differentiation. On the other hand, NT-3 promoted the survival but not the proliferation and/or the differentiation of oligodendrocytes precursors present in the same culture, an effect that was reversed by the addition of neutralizing antibodies against NT-3. Type I or II astrocytes were not affected by NT-3. These results reinforce the role for NT-3 in oligodendrocyte lineage development and allow to dissect the roles of this neurotrophin in survival and in proliferation/differentiation of oligodendrocytes.