Figure 7.

Glomerular inputs connected to multi-glomerular MTCs exhibit a broad underlying tuning profile

(A) Overlay of odor responses of 42 glomeruli innervated by multi-glomerular MTCs (n = 16). Profiles are classified by their signal to background ratio (SBR; orange, SBR>0.5; blue, SBR<0.5). Response profiles show low amplitude responses to all amino acids applied except F.

(B) Representative calcium time courses of glomerular input regions with selective tuning to individual amino acids.

(C) Boxplots of amino acid response peak amplitudes of glomeruli innervated by multi-glomerular MTCs. Mean, dashed white line; median: black line; box outlines 1st and 3rd quartiles.

(D) Boxplots of the lifetime sparseness of the MULTI dataset versus glomerular input level (green). Mean, dashed white line; median: black line; box outlines 1st and 3rd quartiles; ∗∗∗, p ≤ 0.001.

(E) Ranked maximum SBR values to individual odor stimuli among multi-glomerular MTCs (MULTI, orange), glomerular input (green), output (blue), and MTC soma level (red). ∗∗∗, p ≤ 0.001.

(F) Ranked distribution of correlation coefficients between all pairings of response peak amplitude vectors. Correlation coefficients were calculated for different datasets, i.e., glomeruli innervated by the same multi-glomerular MTC (MTC-linked), glomeruli of all multi-glomerular MTCs (MULTI), mixed glomerular input, output, and tubb2b⁺ MTCs. Dashed lines indicate Pearson’s correlation coefficient>0.7. ∗∗∗, p ≤ 0.001; ns, not significant, p > 0.05.

(G) Glomeruli connected to multi-glomerular MTCs functionally cluster in a common region in odor space. Odor space is defined by relative amplitude differences between response to single amino acids. Note: Glomeruli of MTCs 1 and 2 (asterisks, see Figure 6) are outliers. See also Figure S7.