Fig. 1. Effects of 0 and 3 mg/kg midazolam (left) and 0 and 9 mg/kg propofol (right) on spontaneous anxiety (A ) and on memory of aversive effect (B ) are shown. Spontaneous anxiety (Experiment 1) was assessed by the latency to enter a neutral dark compartment when rats were placed in an anxiogenic bright one. Memory of an aversive event (Experiment 2) was assessed by the latency to enter the small dark compartment where rats previously experienced electric foot shocks. Results are expressed on a log scale as mean latency and SD. *P < 0.05 when compared with the 0-mg/kg dose (with Bonferoni's correction for two comparisons).