Dose-response curves of PNs are shifted to left of ORN curves and explain ORN-to-PN transfer functions.

<p>(<b>A</b>) Medians (circles) and quantiles 10% and 90% (vertical dashed lines) of all <i>F</i> measured at a given dose, as shown in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi-1003975-g005" target="_blank">Fig. 5</a>. Dose-firing rate curves of ORN (blue) and PN (red) populations reconstructed from parameters of individual <i>C</i>–<i>F</i> curves shown in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi-1003975-g006" target="_blank">Fig. 6</a>, based on median (solid), 10% most responsive neurons (dashed, based on quantiles 90% for <i>F</i>_M and 10% for <i>C</i>_1/2, <i>n</i>) and 90% less responsive neurons (dash-dotted). (<b>B</b>) Dose-latency curves of ORNs (blue) and PNs (red) based on median, 90% and 10% quantiles. Same representations as in (A) based either on pooled <i>L</i> (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi-1003975-g005" target="_blank">Fig. 5</a>) or on parameters of <i>C-L</i> curves (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi-1003975-g007" target="_blank">Fig. 7</a>). (<b>C</b>) Median transfer function for firing rates (solid, eq. <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi.1003975.e009" target="_blank">9</a>); it can be approximated by <i>F</i>_PN = 62.5/(1+ (1.5/<i>F</i>_ORN)^1.15); inset: detail of most nonlinear part from threshold to ED50 of ORNs. Transfer function for the 10% most responsive neurons (dashed, derived from (A) by coupling most responsive ORNs and PNs) and for the 10% least responsive ones (dash-dotted). (<b>D</b>) Median transfer function for latencies running from right (low doses) to left (high doses) (solid, eq. <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003975#pcbi.1003975.e012" target="_blank">12</a>); inset: linear part from threshold to ED50 of ORNs. Transfer functions for the 10% fastest neurons (dashed) and for the 10% slowest neurons (dash-dot). (<b>E</b>) Distributions of thresholds <i>C</i>₀ in ORNs (blue, <i>N</i> = 38) and PNs (red, <i>N</i> = 37); empirical CDFs (staircases) with fitted normal CDF (solid curve) and corresponding PDF (dashed curve); maximum contrast at <i>C</i>_0Δ = −1.9 log ng (dashed vertical line) with 17% ORNs and 85% PNs activated. (<b>F</b>) Distributions of ED50 <i>C</i>_1/2, same <i>N</i>'s and representation as in (E); maximum contrast at <i>C</i>_1/2Δ = 0 log ng (dashed vertical line) with 2% of ORNs and 98% of PNs above their <i>C</i>_1/2.