Figure 3.
Broader Glomerular Odor Tuning Leads to Less Specific Odor Representations in dfmr1− Flies
(A and B) Cosine (A) and Euclidean (B) distance matrices representing pairwise similarities among glomerular responses to 24 odors in WT and dfmr1− flies (WT, n = 10 flies, 492 glomeruli; dfmr1−, n = 12, 560 glomeruli). Reduced cosines (A) and Euclidean (B) distances (cooler colors) indicate more similar odor representations in dfmr1− flies.
(C and D) Cumulative distribution of cosine (C) and Euclidean (D) distances in WT and in dfmr1− flies. Significantly lower cosine (C) and Euclidean (D) distances indicate more similar odor representations in dfmr1− flies (WT, n = 10 flies, 492 glomeruli; dfmr1−, n = 12 flies, 560 glomeruli; Kolmogorov-Smirnov test; cosine, p = 7.4 × 10−16; Euclidean, p = 4.1 × 10−7).
(E) Normalized odor responses of all individual WT and dfmr1− glomeruli (WT, n = 10 flies, 492 glomeruli; dfmr1−, n = 12 flies, 560 glomeruli). Glomeruli are sorted based on their odor selectivity, from the least selective (top) to the most selective (bottom). Responses are sorted based on their strength, after normalizing to the strongest response of individual glomeruli (warmest colors) on the left. A dashed line is added to help with comparison.
(F) Cumulative distribution of lifetime sparseness for all recorded glomeruli in WT and dfmr1− flies. Reduced lifetime sparseness indicates that dfmr1− glomeruli exhibited broader odor tuning, reflecting reduced specificity (WT, n = 10 flies, 492 glomeruli; dfmr1−, n = 12 flies, 560 glomeruli; Kolmogorov-Smirnov test, p = 9.8 × 10−14).
(G) Cumulative distribution of population sparseness for all measured odors in WT and dfmr1− flies. Lower population sparseness indicates that odors activate more glomeruli in dfmr1− flies (WT, n = 10 flies, 492 glomeruli; dfmr1−, n = 12 flies, 560 glomeruli; Kolmogorov-Smirnov test, p = 8.4 × 10−22).
See also Figures S4 and S5.