Figure 2From: Anxiety- and depressive-like responses and c-fos activity in preproenkephalin knockout mice: Oversensitivity hypothesis of enkephalin deficit-induced posttraumatic stress disorderMean (± SEM) freezing time during situational reminders on Days 2, 7, and 13. Conditioned freezing behavior was assessed in WT-no footshock, ppENK-no footshock, WT-footshock, and ppENK-footshock groups.Back to article page