BACKGROUND: It has been demonstrated that transforming growth factor-β (TGF-β) and brain-derived neurotrophic factor (BDNF) can induce stem cell differentiation into neuron-like cells.OBJECTIVE: To investigate the efficacy of TGF-β and BDNF at inducing the differentiation of adult rat bone marrow stromal cells (BMSCs) into neuron-like cells, both in combination or alone.DESIGN, TIME AND SETTING: A comparative observation experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University between October 2007 and January 2008.MATERIALS: TGF-βand BDNF were purchased from Sigma, USA; mouse anti-rat neuron specific enolase, neurofilament and glial fibrillary acidic protein were purchased from Beijing HMHL Biochem Ltd., China.METHODS: BMSCs were isolated from rats aged 4 weeks and incubated with TGF-β(1μg/L) and/or BDNF (50μg/mL).MAIN OUTCOME MEASURES: Expression of neuron-specific enolase, neurofilament and glial fibrillary acidic protein were determined by immunocytochemistry.RESULTS: BMSCs differentiated into neuron-like cells following induction of TGF-β and BDNF, and expressed both neuron-specific enolase and neurofilament. The percent of positive cells was significantly greater in the combination group than those induced with TGF-β or BDNF alone (P<0.01).CONCLUSION: Treatment of BMSCs with a combination of TGF-β and BDNF induced differentiation into neuron-like cells, with the induction being significantly greater than with TGF-β or BDNF alone.