P>Objective To investigate the morphologic characteristics of neuron-like cells induced from the rat mesenchymal stem cells(MSCs). Methods The rat MSCs from bone marrow were cultured by being adhered to the culture dish.The thirdgeneration of the MSCs were induced by the neonate rat brain homogenate supernatant for 48 hours.The morphological characteristics and the ultrastructures of both non-induced and induced MSCs were observed under the inverted microscope and the electron microscope.The property of the induced cells was identified by using immunocytochemical method. Results Under the inverted microscope MSCs showed spindle or polygon-shaped cell bodies and the nuclei with one or two nucleoli were located in the middle of the cells.After the inducement the cells appeared neuron-like with axonlike and dendrite-like processes.The neuron-like cells were neuron special endolase(NSE),neurofilament protein(NF) positive and glial filbrillary acidic protein(GFAP) negative by irnmunocytochemical staining.Under the electron microscope the MSCs had plentiful cytoplasm and organelles and had an obvious nuclei containing a nucleoli.There were a lot of microvilli on the surfaces of the MSCs.The neuron-like cells had plentiful cytoplasm and irregular nuclei with one to three nucleoli.There were also plenty of microvilli on the cell surfaces.Conclusion MSCs are one kind of multipotent stem cells and can differentiate neurons with matured organelles induced by the neonate rat brain homogenate supernatant./P>