Figure 2.

(A) Effect of SUN on contextual memory in mice tested 24 h after training. Freezing behaviors were scored over the 3-min test and represent mean ± SEM. (B) Effect of SUN on immediate freezing responses measured 30 sec after training (to control for acute effects of treatments on freezing behaviors). *P < 0.05 by one-way ANOVA. Rolipram-positive control (0.1 mg/kg i.p.) was administered 20 min before training session, and compared to its vehicle control (1% DMSO). SUN was administered (3, 10, 30 mg/kg, p.o.) 2 h before training, and compared to its vehicle control (50 mmol\L isotonic phosphate buffer, 0 mg/kg in figure). N = 10 animals per group.