Fig. 5. Effects of inhibition of Rac or Cdc42 CRIB activity on cytoskeletal morphology. All growth cones were exposed to an EF (cathode at left) for 5 hours. (A) No drug + EF. (B-D) Growth cones treated with Rac 17-32 (rac). Note that microtubules (first column) appear less adherent to each other along their lengths. Numerous, uniformly distributed filopodia are present but lamellipodia are not well formed. (E,F) Growth cones in Cdc42 17-32 peptide (cdc). Microtubules (first column) appear loosely adherent to each other and they splay into the peripheral region of the growth cone more than when treated with Rac 17-32. Filamentous actin staining (second column) reveals large, well-spread lamellipodia and relatively fewer filopodia than when treated with Rac 17-32. When they are present, filopodia face the cathode. Bars, 10 µm.