Fig. 2

Modulated GMF with increased intensity induces positive geotaxis. a Left: Comparisons of the geotactic positioning under the GMF conditions with modulated intensities. A positive geotaxis was induced in conditions b and c. Error bars: SEM. n.s.: not significant. ***, P < 0.005; ****, P < 0.001 by ANOVA Tukey’s test. (n = 10 trials). Right: A representative image of geotactic positioning under the sham and b, respectively. b, c Comparisons of the geotactic positioning of the wild-type flies between light (500 lx) versus dark (0 lx) conditions under the near-zero GMF condition and the GMF condition b in Fig. 2a, respectively. Note the increase of positioning score of the sham samples under the dark condition. −; near-zero GMF, +; GMF condition b. Error bars: SEM. n.s.: not significant. ***, P < 0.005; ****, P < 0.001 by Student’s t-test. d Schematic drawing of the associative learning assay using food as an unconditioned stimulus and the non-geotactic GMF as a conditioned stimulus. The GMF denotes the non-geotactic GMF a. Note that the test tubes were inverted during the rest and the GMF was provided from the bottom side of the tubes. The homogeneous space for the GMF is marked as dashed rectangles. e Comparisons of the geotactic positioning induced by the control, trained, and test conditions in the presence of the ambient GMF condition (Sham) or the GMF stimulus, or either one associated with food. GMF, the non-geotactic GMF condition a in Fig. 2a. Food, the rearing diet. Error bars: SEM. n.s.: not significant. ****, P < 0.001; *****, P < 0.0001; ***, P < 0.005 compared to the sample of the middle group, associated with the GMF alone and then tested under the same GMF, by ANOVA or Student’s t-test (n = 10 trials)