A graph showing the effects of acute treatment with the crude extract of Erythrina falcate (CE) (A), buthanolic fraction (BUF), subfraction from BuF (B) and the flavonoidic fractions (FfA and FfB) (C) on the acquisition and extinction of fear memory as evaluated by one-trial, step-down inhibitory avoidance (IA). The animals were subjected to five retention sessions (T1-T5) of IA tasks. The values of the step-down latencies are expressed as the as mean differences of the latencies between Training and Test sessions (dL = mean ± EPM). *P < 0.05, **P < 0.01 and ***P < 0.001. No footshock was administered during the test sessions. The interval between T1, T2 and T3 was 24 h. T4 and T5 comprised 240- and 480-h intervals, respectively, after training. No drugs were administered during the test sessions. Two-way ANOVA was used to consider the two fixed factors (group and trial) and one random factor (rat). Repeated measures were employed for the intragroup comparison of the retention test data (CS presentation).