Figure 1.

Persistent Odor Tracking Is Motivated by Hunger

(A) Top: Spherical-treadmill assay for olfactory stimuli.

(B) Top: Average running speed with SEM (mm/s) of 18 wild-type Canton S flies under repeated vinegar exposure for 10 trials. Shaded areas represent the odor exposure duration. Bottom: Average running speeds of flies during vinegar exposure were significantly higher compared to the speeds observed during pre- and post-stimulation periods.

(C) Top: Average absolute turning speed with SEM (deg/s) of 18 flies under repeated vinegar exposure for 10 trials. Bottom: The absolute turning speed under vinegar was significantly lower than the turning speed recorded in pre- and post-stimulation periods.

(D) Average running speed with SEM of 18 wild-type flies over time for each of the individual 10 trials.

(E) Comparison of average running over trials.

(F) Average running speed with SEM of fed (0 h) and hungry (24 and 48 h) flies during trial 1 and trial 10 of repeated vinegar exposure.

(G and H) Average running speed with SEM during odor stimulation during trial 1 to 10 for fed, 24 h and 48 h starved flies. The boxplot (G) displays the Tukey’s post hoc analysis for the main group effect.

(I and J) Average running bout times with SEM during open-loop odor exposure for fed and food-deprived flies over 10 trials. The boxplot (J) displays the Tukey’s post hoc analysis for the main group effect.

(K) Left: Schematics for the closed-loop assay. Right: Average running bout times with SEM during closed-loop odor exposure for differentially food-deprived flies over 10 trials.

(L) Total running times of fed and starved flies during odor stimulation.

(M) Average summed running bout times during 10 trials for all groups in closed-loop experiments under vinegar exposure.

For all analyses, statistical notations are as follows: ns, p > 0.05; ∗, p < 0.05; ∗∗, p < 0.01; ∗∗∗, p < 0.001; ∗∗∗∗, p < 0.0001. In all panels, error bars denote SEM.