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Objective Netrin-1 (NT-1) is one of the axon-guiding molecules that are critical for neuronal development.NT-1 stimulates proliferation and migration of human cerebral endothelial cells in vitro and promotes focal neovascularization in adult brain in vivo.It is unknown whether NT-1 improves long-term functional outcome after ischemic stroke.The aim of this study is to determine whether hyper-expression of NT-1 through adeno-associated virus (AAV)-mediated gene transfer enhances neurovascular remodeling and improves functional outcome in mouse model of focal cerebral ischemia.Methods AAV-NT-1 virus was stereotactic injected into the basal ganglia of male CD-1 mice (n=30).Seven days after injection, these mice underwent 60 minutes of transient middle cerebral artery occlusion (tMCAO) followed by 1 to 4 weeks of reperfusion.Expression of NT-1 and its receptors was quantified by Western blot and immunostaining.Infarct volume and behavioral analyses were performed after tMCAO.Synchronic radiation angiography was used to detect the changes of cerebral vasculature.Results NT-1 expression in the ischemic hemisphere was enhanced after AAV-NT-1 gene transfer.Both neurons and astrocytes but not endothelial cells expressed NT-1.NT-1 receptors (DCC and UNC5H2) also expressed in neurons and astrocytes.Hyper-expression of NT-1 decreased infarct volume in the AAV-NT-1-transduced mice compared to the control (P<0.01).Long-term observation demonstrated that neurobehavioral outcomes were greatly improved in the AAV-NT-1-tranduced mice compared to the control (P<0.05).Further study demonstrated that the microvessel counts were significantly increased in the AAV-NT-1 transduced mice (P<0.05).Synchrotron radiation angiography showed that the brunches of MCA was increased in NT-1 treated mice.Conclusion Our data demonstrate that NT-1 hyper-expression reduced ischemic injury and promoted functional recovery.This may due to enhancement of focal neovascularization.