NEUROD1 and transient ischemic attack: In the present study, a retroviral solution (1.5–2.0 × 107 /ul) of mock pMX-GFP (n = 13) or pMX-Ascl1/Sox2/NeuroD1 (ASN) (n = 14) was directly injected into the ipsilateral striatum and cortex 3 days after 30 min of transient cerebral ischemia.