IF experiments were performed as previously described (Welshhans and Bassell, 2011 (link)), and the following primary antibodies were used: mouse anti-paxillin antibody (1:500), mouse anti-vinculin antibody (1:500), rabbit anti-RACK1 antibody (1:500; Santa Cruz Biotechnology), mouse anti-RACK1 antibody (1:500; Santa Cruz Biotechnology), rabbit anti-ribosomal protein S6 antibody (1:100; Santa Cruz Biotechnology), mouse anti-ribosomal protein S6 antibody (1:100; Santa Cruz Biotechnology), and mouse anti-ribosomal RNA 5.8s Y10b antibody (1:100, Abcam). The following secondary antibodies were used: goat anti-mouse Alexa 488, goat anti-rabbit Alexa 488, goat anti-mouse Cy3 and donkey anti-mouse Alexa 647 (all from Jackson ImmunoResearch). Rhodamine phalloidin or Alexa Fluor 350 phalloidin (Life Technologies) was also added in experiments during the secondary antibody incubation to stain F-actin for visualization of growth cone area.