Objective To investigate the effects of passaging on the proliferation,differentiation and apoptosis of neural stem cells.Methods Neural stem cells both from prime culture(P0) and twice-passaged culture(P2) were tested by enzyme immunoassay for proliferation and fluorescent activated cell sorting for apoptosis by Annexin V-FITC and propidium iodide.After being enduced to differentiation for 7 days,they were detected by the neuronal marker MAP2 and the astrocyte marker GFAP with nuclei staining by Hoechst 33342 additionally.The ratios of MAP2+/Hoechst+ and GFAP+/Hoechst+ were calculated.Results The absorbance of NSCs from P0 and P2 is 1.1899?0.0485(n=13)and 0.3526?0.1053(n=11)(P=0.000).Analyses of apoptosis using cytoflurometry are 40.91%?12.74% for P0(n=8)and 24.31%?13.01% for P2(n=9,P=0.018).The ratios of MAP2+/Hoechst+ and GFAP+/Hoechst+ of NSCs from P0 were 58.81%?9.69%(n=10)和22.85%?4.36%(n=10) while the ones for P2 were 27.84%?5.70%(n=10)and 49.32%?6.95%(n=10,P=0.000).Conclusions By passaging the proliferation and apoptosis of NSCs decreases and they differentiate into less neurons and more astrocytes.

Objective With the comparison of the proliferation,differentiation and apoptosis of neural stem cells from different embryonic stages,to obtain the biology of NSCs and the development mechanism of embryonic cortex underlining.Methods After the prime culture of NSCs from forebrain cortice of different embryonic stages(E14,E18 and E20),enzyme immunoassay for NSCs proliferation was carried out.After 7 days of differentiation induced by fetal bovine serum,they were detected by the neuronal marker MAP2 and the astrocyte marker GFAP with nuclei staining by Hoechst 33342 additionally.The ratios of MAP2+/Hoechst+ and GFAP+/Hoechst+ were calculated.Fluorescent activated cell sorting for apoptosis were used to detect the apoptosis of NSCs by Annexin V-FITC and propidium iodide.Results The absorbance of NSCs is 1.1771?0.0422(n=22) for E14,0.4127?0.0328(n=23) for E18,and 0.4127?0.0456(n=16) for E20(P

Objective To investigate the met ho ds of isolation,culturing and passaging of neural stem cells originated from ra t embryonic brains.Methods The neural stem cells were obtained from the brain tissue of rat embryos.They were cultured and passaged with serum-free medium.T hey were identified with Nestin and stained with NF68,GFAP,and GalC after diff erentiation.Results We cultured the neural stem cells through several passages .With the help of serum,they differentiated to neurons,astrocytes and oligode ndrocytes.Conclusion The neural stem cells derived from rat embryonic brains a re able to proliferate and multiplepotent for differentiation.