Abstract: Objective To explore the differentiation of rat bone marrow mesenchymal stem cells(BMSCs) into dopaminergic neurons EM>in vitro/EM> after induced by sonic hedgehog (SHH) and fibroblast growth factor-8 (FGF-8). Methods The BMSCs derived from rat bone marrow were cultured and passaged in vitro. After being induced by basic fibroblast growth factor(bFGF) for 24 hours, the BMSCs were incubated with SHH and FGF-8 for 12 days. Then the expressions of Nestin, neuron specific enolase(NSE), glia fibrillary acid protein(GFAP), tyrosine hydroxylase(TH), vesicular monoamine transporter-2(VMAT2), proliferating cell nuclear antigen(PCNA), Bcl-2, cyclindependent protein kinase2(CDK2) and Cyclin B1 were detected by immunocytochemical and immunofluorescence methods. Results Under the inverted microscope, the induced BMSCs showed typical neuronal morphological characteristics after induction, and they downregulated PCNA, CDK2 and Cyclin B1.The induced cells also expressed Nestin, NSE, TH and VMAT2 in high degree and GFAP in low degree. The percentages of induced cells and uninduced BMSCs positive for TH were (46

Key words: Mesenchymal stem cell, Dopaminergic neuron, Sonic hedgehog, Fibroblast growth factor-8, Cell culture, Rat