Figure 1.
Schematic of the experimental design used in this study. On Day 0, animals in Cohort 1 were fear conditioned 30 min after ICV infusion of vehicle (VEH) or PACAP (1.5 μg). Sixty minutes later animals were sacrificed (SAC) for immunohistochemical analysis of Arc expression. Twenty-four h later (Day 1), animals in Cohort 2 treated with VEH or PACAP on Day 0 were tested for conditioned freezing and sacrificed 60 min later for immunohistochemical analysis of Arc.