Fig. 8. Association of Rac 1 with laminin-induced outgrowth in the presence of CD. (A) Localization of Rho family proteins in growth cones treated with CD for 15 minutes followed by laminin for 25 minutes. Cultures were fixed and double stained for each GTPase and actin with either phalloidin and antibody to Rac 1, or an antibody to actin together with antibodies to Rho and cdc42. Only Rac 1 co-concentrates with actin. Bar, 10 µm. (B) Rac 1 is intimately associated with bundled microtubules. Rac 1 (red) colocalizes with bundled microtubules (tubulin, green) at the leading edge of neurites induced by laminin. Bar, 10 µm.