Effect of yohimbine treatment on strength and specificity of memory in the dual-event inhibitory avoidance task in mice. (A) We found a main effect of yohimbine treatment on 72 h retention latencies (following training with a 90 sec interval and 0.38 mA footshock), caused by longer retention latencies across test contexts of mice administered the two higher dosages of yohimbine (1 and 3 mg/kg). No significant yohimbine treatment × test context interaction effect was found (vehicle: n = 17, yohimbine 0.3 mg/kg: n = 16, yohimbine 1 mg/kg: n = 19, yohimbine 3 mg/kg: n = 20). (B) We only counterbalanced the order of retention testing in the Shock box and Non-Shock box (Novel box always last) and lowered the footshock intensity (0.20 mA). Still, we found no effect of yohimbine treatment or yohimbine treatment × test context interaction on retention latencies (vehicle: n = 14, yohimbine 1 mg/kg: n = 15, yohimbine 3 mg/kg: n = 17). Task parameters changed relative to the prior task conditions are depicted in bold. Data represent mean + SEM. Dots indicate individual data points. (❖) P < 0.05, (❖❖) P < 0.01: different from saline.
