The effect of ITGB1 knockdown on proteins of ITGB1/pFAK/RhoA and the axonal growth. Representative Western blots and quantification data (A) show levels of ITGB1, pFAK, FAK and RhoA proteins in distal axons (A, axon) and cell bodies (A, cell body) of cortical neurons transfected with siRNA against ITGB1. *, p<0.05 vs control. The quantitative results (B) show the effect of ITGB1 knockdown on distal axonal growth after axonal application of CSPGs, sildenafil (sild), or CSPGs+sildenafil (CSPGs+sild). Protein levels of p85 and β-actin were used as internal controls for the distal axons and cell bodies, respectively.