Intra-basolateral amygdala naloxone blocks incentive learning but does not affect changes in palatability or the retrieval of incentive value. (A) Palatability: see the legend for Fig. 1A. Assessment by 2-way ANOVA of lick frequency data following intra-basolateral amygdala infusion found a main effect of deprivation (F1,127 = 11.88, P = 0.0008), no effect of drug (F1,127 = 1.29, P = 0.25), and no interaction between drug and deprivation (F1,127 = 0.02, P = 0.88). (B) Incentive learning: see the legend for Fig. 1B. Assessment by 2-way ANOVA found a main effect of deprivation (F1,85 = 8.30, P = 0.005) and drug (F1,85 = 3.72, P = 0.05) and an interaction between drug and deprivation (F1,85 = 4.79, P = 0.03). (C) Naloxone on test: seeking response rates, normalized to training baseline, are shown for the rats receiving naloxone immediately before the non-rewarded test. Assessment by 3-way ANOVA found a main effect of deprivation (F1,127 = 11.90, P = 0.001) and of drug during re-exposure (F1,127 = 5.95, P = 0.016) but no effect of drug on test (F1,127 = 2.62, P = 0.11). There was an interaction between drug and deprivation during re-exposure (F1,127 = 9.58, P = 0.002). No other interactions were significant (all Fs < 1). n = 26 in both replications. *, P < 0.05; **, P < 0.01.