Figure 5.

The effect of Radix Polygalae (RP) on cued fear memory acquisition, extinction and renewal. The average % freezing of eight sessions (acquisition) or five sessions (extinction and renewal) are plotted. Repeat measure analysis of variance (ANOVA) showed within-group (procedure) effect [F(3.5, 94.3) = 17.3, p < 0.001, η² = 0.391] but non-significant between-group (treatment) effect [F(2,27) = 0.73, p = 0.49, η² = 0.052] and within–between interaction [F(7.0, 94.3) = 2.0, p = 0.06, η² = 0.13]. In the control group, fear reduced during the extinction training (first extinction training block vs. sixth extinction training block; p = 0.048), but fear did not increase during the renewal procedure. In both RP1 and RP10, fear extinction and fear renewal were not significant (fear extinction in RP1; p = 0.062). Data represent mean ± SEM. control: DW; RP1: Radix Polygalae 1 mg/kg p.o. 10 days; RP10: Radix Polygalae 10 mg/kg p.o. 10 days.