Fig. 2.

Optogenetic activation of KCs does not alter locomotion or odor responses. a–c Conditional optogenetic activation of KCs does not change larval velocity (a, b) and accumulated distance (c). The light regime is indicated by the red and blue rectangles: larvae were monitored under red light for 1 min, subsequently under blue light for another minute. d–g Similarly, innate odor preference to OCT (d) and diluted AM (e) is not altered due to conditional optogenetic activation of KCs. In line, experimental larvae showed normal performance in an odor discrimination task using OCT and either pure AM (f) or 1:40 diluted AM (g). h, i Conditional optogenetic activation of KCs is sufficient to induce an appetitive memory using a 2-odor reciprocal training regime indicating that experimental larvae can distinguish different odors despite artificially activated KCs. AM: amylacetate; ChR2-XXL: channelrhodopsin2-XXL; KCs: Kenyon cells; OCT: octanol; w: w¹¹¹⁸. The number below the box plots refers to the N number. A pairwise Student’s t test or pairwise Wilcoxon test (both including Bonferroni-Holm correction) was used. Significance levels: ^n.s.p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001. Error bars (a) represent the standard error of the mean. Data are mainly presented as box plots, with 50% of the values of a given genotype being located within the box, and whiskers represent the entire set of data. No data were excluded. Outliers are indicated as open circles. The median performance index is indicated as a thick line within the box plot