Objective: To examine the responsivenss of newborn rat mesencephalic progenitors to different chemicals, looking for a way to efficiently enhance their neurogenesis in vitro. Methods: Newborn rat midbrain-derived neural progenitors were used to examine the effects of different chemicals. Eight different chemicals, glial cell line-derived neurotrophic factor (GDNF),ciliary neurotrophic factor (CNTF),interleukin-1 alpha(IL-1α),puerarin, arctiin ginsenoside Rg1,gastrodin or 17 beta-estradiol,were screened for their ability to induce the mesencephalic progenitors toward neuronal phenotype. Using immunocytochemistry,the percentage of microtubule-associated protein-2ab (a specific neuron marker)-positive cells was calculated. Results: In contrast to spontaneous differentiation,only IL-1α was found to promote neuron-oriented differentiation on mesencephalic progenitors while GDNF,CNTF and gastrodin showed an inhibitory effect, and the rest chemicals had no effect on neuronal differentiation. Conclusion: Fate of newborn rat mesencephalic progenitors can be manipulated by environmental signal in a neuronal phenotype before cell transplantation.Further investigation may contribute to find gene targets to control linage specification of neural progenitors.

Objective To examine wether cytokine dose and extremely low\|frequency electromagnetic field(ELF\|EMF) would influence the effects of ciliary neurotrophic factor (CNTF) and interleukin\|1 alpha(IL\|1α) on the differentiation of neural stem cells(NSCs) from midbrains of new\|born rats. Methods Differentiation of NSCs,exposed or unexposed to ELF\|EMF,was induced by CNTF or IL\|1α at different concentration for 5 days.Cells then were fixed and processed for immunofluorescent staining to detect the neuron\|specific marker,microtubule\|associated protein 2ab(MAP2ab),thus the percentage of MAP2ab\++ cells was calculated. Results In contrast with the control,low\|dosed CNTF and IL\|1α increased the percentage of neuron\|fated cells while high\|dosed CNTF significantly decreased the percentage of MAP2ab\|positive cells( P 0\^01).ELF\|EMF exposure enhanced the stimulating effect of low\|dosed CNTF;The most exciting finding was that the EMF converted the inhibitory effect of high\|dosed CNTF on neurogenesis to the stimulative effect.The EMF diminished the promoting effects of low\|dosed IL\|1α as well as failed to influence the high\|dosed IL\|1α effect.Conclusion Inductive effects of cytokines on NSCs differentiation are dose\|related.Coeffects of ELF\|EMF and cytokines would not be simply added up or subtracted,implying that the role of organism EMF during CNS development should not be ignored.EMF may be a promising strategy for manipulating NSCs differentiation.\;[

Objective. To examine the effect of electromagnetic fields (EMF) (20 Hz, 8 mT; 5 Hz, 8 mT) on the neuron-orientated differentiation of neural stem cells (NSCs) from midbrains of new-bom rats. Method. Differentiated NSCs were exposed to EMF for 2 x 15 min per day lasting for I d, 5 d, or 10 d. The sham-exposure controls were correspondingly established. Cells were fixed and processed for immunofluorescent staining using the antibody against neuron-specific marker MAP2, then the percentage of MAP2+ cells was calculated. Result. The two EMFs promoted the differentiation of a neuronal fate in different ways. Both of them came into effect even after 1 d exposure. When cells exposed to the 20 Hz EMF, the percentage of neuron-orientated cells gradually increased with longer-term exposure and the most significant effect appeared in 10 d group while that happened in 5 d group under the condition of 5 Hz EMF. The effect contrasted horizontally, significant differences between the two EMFs were observed only at 10 d groups, 20 Hz EMF having more favorable effect than 5 Hz EMF. Conclusion. 20 Hz and 5 Hz EMF could promote the differentiation of midbrain NSCs to a neuronal phenotype in different ways, suggesting that the physical induction might be another strategy to manipulate the differentiation of NSCs.