FOS and Anxiety: Exposure to uncontrollable stress [16], or other anxiety-related stimuli including anxiogenic drugs such as the adenosine receptor antagonist caffeine, the serotonin 5-HT2A/2C receptor agonist m-chlorophenyl piperazine (mCPP), and the partial inverse agonist at the benzodiazepine site on the GABAA receptor N-methyl-beta-carboline-3-carboxamide (FG-7142) [1], the anxiety-related neuropeptide urocortin 2 [64], and social defeat [13] increase c-Fos expression within the midrostrocaudal and/or caudal parts of the DR, but not the rostral DR.