Reports of neuronal differentiation of bone marrow derived mesenchymal stem cells (MSCs) suggested the possibility that these cells could serve as a source of treatment for spinal cord injury. However, the percentages of neuron-like cells differentiated from the MSCs were relatively low both in vitro and in vivo. Here, we investigated whether co-culture of human neurotrophin-3 (NT-3) gene modified Schwann cells (SCs) and human NT-3 receptor tyrosine protein kinase C (TrkC) gene modified MSCs could increase differentiation of neuron-like cells from MSCs. It was shown that MSCs were significantly promoted to differentiate into neuron-like cells, as evidenced immunocytochemically by the expression of neuronal markers, including nestin, beta-III-tubulin, MAP2 and PSD95, 7 days after co-culture. However, the expression of glial fibrillary acidic protein (GFAP)--an astrocyte marker in these cells--was not so obvious. These results demonstrate that the binding of overexpressed NT-3 in SCs and its receptor TrkC in MSCs can be considered to stimulate the increased rate of neuronal differentiation.