Extended Data Fig. 9. Further characterization of functional cohorts.
a, Composition of functional MC cohorts. For each pair of bile acid odors (X-axis), a functional MC cohort was defined as the 10 MCs that contribute most to the correlation between odor-evoked activity patterns at t1 (highest ri,t1). Gray pixels denote membership of each MC (Y-axis) in each cohort. Cohorts for different odor pairs overlapped substantially. Consistent with this observation, the mean Pearson correlation between tuning curves of MCs at t1 was significantly higher within cohorts (r = 0.56 ± 0.40; mean ± s.d.) than across all MCs (r = 0.01 ± 0.38; p = 10-84; two-sided Wilcoxon rank-sum test). Furthermore, we analyzed the mean tuning correlation at t1 among the 16 MCs that were not part of cohorts themselves but provided the highest number of disynaptic input connections to neurons inside cohorts (r = 0.23 ± 0.52; mean ± s.d.). This tuning correlation was lower than the tuning correlation within the cohort but still significantly higher than the mean tuning correlation across all MCs (p = 10-40; two-sided Wilcoxon rank-sum test). Similarly, the mean tuning correlation at t1 among the 16 MCs that received the most disynaptic output connections from neurons inside cohorts (r = 0.17 ± 0.53; mean ± s.d.) was lower than the tuning correlation within the cohort but significantly higher than the mean tuning correlation across all MCs (p = 10-17; two-sided Wilcoxon rank-sum test). b, Black: frequency of each MC-IN-MC triplet motif in MC cohorts (n = 6 cohorts for each motif). Dots show means, error bars show s.d., box plots show median, 25% percentile, and 75th percentile. Gray: frequency of MC-IN-MC triplet motifs among randomly selected MC subsets of the same size (n = 10 MCs; n = 600 repetitions for each motif). Frequency of occurrence is normalized to the mean frequency in random subsets for each motif. **, p < 0.01; ***, p < 0.001 (two-sided Wilcoxon rank-sum test). P-values: 0.002, 10-5, 0.0008, 0.0001. We also observed that the 10 INs receiving the largest number of MC inputs from each cohort were 1.7 times more likely to make direct connections than random subsets of INs (p = 0.007; two-sided Wilcoxon rank-sum test). c, Blue: mean activity of the 10 MCs in the functional cohort defined by responses to TCA and GCDCA (example odors in Fig. 5b). Green: mean activity of the 10 INs that were included in activity measurements and provided the highest synaptic input to the MC cohort. As expected, IN activity increased while MC activity decreased during odor application.