Effect of pretest administration of A-988315 on stress-induced increases in plasma ACTH and corticosterone levels. (a) Plasma ACTH levels (in pg/ml) as assessed immediately after the memory retrieval test. (b) Plasma corticosterone levels (in ng/ml) of rats as assessed immediately after the memory retrieval test. All data are expressed as mean+SEM. *P<0.05 compared with the corresponding water group. ♦♦P<0.01 compared with the corresponding non-stress group. Number of rats per group—non-stress groups: water, n=21; 20 mg/kg, n=21 for ACTH, n=20 for corticosterone; 60 mg/kg, n=21; and stress groups: water, n=21; 20 mg/kg, n=19; 60 mg/kg, n=21.