Fig. 1
From: Ingestion of artificial sweeteners leads to caloric frustration memory in Drosophila
Flies learn to devalue sugar value through taste recognition and a post-ingestion mechanism. a Pre-feeding flies for 1 min with non-nutritious l-glucose 24 h before olfactory conditioning with the same sugar induces significantly lower STM scores as compared to non-pre-fed flies or flies pre-fed with classical medium (F (2,52) = 12.63; p < 0.0001; n ≥ 18; p > 0.999 in post hoc analysis between non-pre-fed flies and flies pre-fed with medium). In contrast, pre-feeding flies with nutritious d-glucose does not affect olfactory memory scores as compared to non-pre-fed flies or flies pre-fed with medium (F (2,52) = 0.553; p = 0.578; n ≥ 18). However, pre-feeding flies with a mixture of d-glucose and phlorizin induces significantly lower olfactory memory scores as compared to d-glucose pre-fed flies (t-test, t 37 = 2.544; p = 0.015; n ≥ 19). b PER (Proboscis Extension Response) scores with increasing concentrations of l-glucose in flies pre-fed with l-glucose or a mixture of d-glucose + phlorizin 24 h are similar to flies pre-fed with d-glucose or medium, as well as non-pre-fed flies (F (16,1032) = 0.906; p = 0.494; n ≥ 47). c Flies pre-fed and conditioned with arabinose display significantly lower memory scores as compared to non-pre-fed flies conditioned with arabinose (t-test, t 42 = 2.056; p = 0.046; n ≥ 21). d Pre-feeding flies with l-glucose and conditioning them with arabinose induces significantly higher memory scores in comparison to flies pre-fed and conditioned with l-glucose (t-test, t 18 = 2.188; p = 0.042; n = 10). See also Supplementary Fig. 1. Means are ± SEM; statistical tests: t-test, one-way ANOVA, two-way ANOVA, and RM-ANOVA; NS: p ≥ 0.05; *p < 0.05 in comparison between two groups for t-test and in post hoc comparisons with other groups for ANOVA
