Stress-induced changes in fear extinction-mediating brain regions. Stress produces a range of morphological, electrophysiological and molecular changes in the prefrontal cortex, hippocampus, and amygdala that parallel extinction abnormalities. BLA, basolateral nucleus of the amygdala; CeA, central nucleus of the amygdala; IL, infralimbic cortex; PL, prelimbic cortex.