Fig 3. Ablation of potential 5-HT_2A receptor cells throughout development impairs aversive olfactory learning and memory.

5-HT_1A-, 5-HT_1B-, 5-HT₇-, and 5-HT_2A-Gal4 lines were crossed with UAS-hid,rpr to genetically induce apoptosis in potential 5-HT receptor cells. In addition, Gal4 lines and UAS-hid,rpr were crossed with w¹¹¹⁸ to obtain heterozygous genetic control larvae. (A) provides a color scheme for the three different groups used in each experiment. Appetitive olfactory learning and memory using fructose reinforcement is shown at the top (B-E). Aversive olfactory learning and memory is shown at the bottom (F-I). In most cases, experimental larvae and genetic control groups behaved similar. However, ablation of 5-HT_2A-Gal4 positive cells specifically impaired aversive olfactory learning and memory (I), while leaving appetitive olfactory learning and memory intact (E). Sample size (n = 10–14) is indicated at the bottom of each box plot. Differences against zero are given at the top of each box plot. Differences between all three groups or individual groups are shown at the bottom of the panel. Visualization of statistical evaluations: if only n.s. is shown the initial Kruskal-Wallis test (KWT) did not suggest for a difference between the three groups (p > 0.05). When differences between each group are shown this provides the results of the Wilcoxon rank-sum tests with Bonferroni corrections (BWRT) as the initial KWT suggested for singnificance (p < 0.05). *** (p < 0.001), ** (p < 0.01), * (p < 0.05), n.s. (not significant p ≥ 0.05).