【Objective】 To investigate the relationship between the alteration of Sema3A and Nrp-1 mRNA expression and the neurite network damage after oxygen glucose deprivation (OGD) in cultured rat cortical neurons. 【Methods】 Cultured cortical neurons of newborn SD rats were randomly divided into control group and OGD treatment group. Neuronal survival rate was assayed with MTT method. Morphological changes of neurite network were observed with beta Ⅲ tubulin (βⅢ-tubulin) immunofluorescence staining. The expression of Sema3A and Nrp-1 mRNA were detected by real-time PCR. The effect of exogenous Sema3A protein on the axonal outgrowth was measured with βⅢ-tubulin immunofluorescence staining. 【Results】 Treated with OGD

the neuron survival rate reduced in a time-dependent manner(P < 0.01). OGD 4 h led to serious damage of neurite network. After OGD 4 h and 6 h

the mRNA expression of Sema3A obviously increased (P < 0.01); and after OGD 6 h

the mRNA expression of Nrp-1 was also significantly up-regulation(P < 0.01). The outgrowth and extension of neuron axon were obviously inhibited by the treatment with exogenous Sema3A (5 mg/mL)(P < 0.01).【Conclusion】 OGD can induce up-regulation of Sema3A and Nrp-1 mRNA

and exogenous Sema3A protein inhibits axon outgrowth in vitro. Sema3A/Nrp-1 may participate in the pathophysiology process of neurite damage and neuron apoptosis in cultured neuron of OGD treatment.