Objective  To explore the effect of the complex containing neuron stem cells (NSCs) and endothelial progenitor cells (EPCs) after being transplanted to ischemia and reperfusion rat model on the differentiation of neural stem cells to neuron and synapse formation.   Methods  Totally 300 SD adult male rats were randomly divided into sham operation group

middle cerebral artery occlusion (MACO) model group

MACO+NSCs group

MACO+EPCs group

and MACO+complex group

and every group were further divided into 6 subgroups according to time points 1

3

7

14

30 and 60 d after operation

NSCs were isolated from the hippocampus of neonatal SD rats born in 24 h and identified with Nestin staining. EPCs were obtained from the artery blood of SD rats and verified with immunocytochemical stainings of CD31 and CD34 after culture. NSCs and EPCs were cultured together to produce the complex with aid of laminin. Then normal saline

the NSCs

EPCs

or complex (2×10

10

/L) were transplanted into the ischemia penumbra of corresponding model rat brain

  sham control or MACO rats. The differentiation of NSCs

the expression of P38

synapsin-I

mRNA of connexin 43 were observed with double label immunofluorescence technique

immunohistochemical method

RT-PCR and Western blot analysis in ischemic penumbra.   Results  Compared with other groups

there were more double Brdu and neural special enolase positive cells in MACO+complex group with the increased expression of P38. RT-PCR and Western blot analysis indicated that MACO+complex group had significantly higher expressions of synapsin-I at mRNA and protein levels in ischemic penumbra

and so did the mRNA expression of connexin 43.   Conclusion  The transplantation of the complex of NSCs and EPCs improves the NSCs differentiation to neuron

synapse formation and reconstruction of neural network.