FIGURE 5.

Odor-electric shock learning and memory in Drosophila larvae depends on the applied voltage of the electric shock. (A) Timescale of associative conditioning using 10 cycles, different voltages for electric shocks (60, 90, and 120 V) and continuous blue light with an intensity of 100%. For the olfactory preference test amyl acetate with a dilution of 1:500 was used. (B) Using 60 V in the training procedure led to a reduction of olfactory preferences for Or47-Gal4/UAS-ChR2-XXL larvae compared to both genetic controls (Or47-Gal4/+ and UAS-ChR2-XXL/+) (Tukey post hoc test, p = 0.001, p = 0.0168, respectively). Both genetic controls showed olfactory preferences, which are statically significant from zero (one sample t-test, p < 0.0001 for both groups), whereas Or47-Gal4/UAS-ChR2-XXL larvae showed an olfactory preference, which is not statistically significant from zero (one sample t-test, p = 0.068). (C) Using 90 V in the training procedure led to a reduction of olfactory preferences for all three groups, which are statistically not significant from each other (one-way ANOVA, p = 0.5917). All three groups showed olfactory preferences, which are statically significant from zero (one sample t-test, p = 0.0375, p = 0.0004, p = 0.0025, respectively). (D) The olfactory preference for amyl acetate conditioned with 120 V was already analyzed in Figure 4D and is just shown for comparison. Differences between groups are depicted below the respective box plots, at which ns indicates p ≥ 0.05. Different lowercase letters indicate statistically significant differences at level p < 0.05. Small circles indicate outliers. Sample size is indicated with the letter n.