bFGF expression is differentially altered following cocaine seeking or extinction in drug- and learning-related brain regions. A schematic depiction of interacting brain regions that are associated with drug-associated learning and extinction, and how bFGF expression is altered in them following cocaine seeking (left), extinction (right), or both. bFGF expression in IL-mPFC, NAc-Core, and NAc-Shell is increased following drug seeking (Coc-NoExt; left; black), which is reversed following extinction (Coc-Ext; right; white). Conversely, bFGF expression is increased following extinction in BLA (Coc-Ext; right; black), but is unchanged following drug seeking (Coc-NoExt; left; gray). Finally, bFGF expression is not significantly changed in PL-mPFC, dHipp, or vHipp (left and right; gray). Gray = no change in expression; white = decrease in expression; black = increase in expression.