The relationship between ORN firing-rates and PN firing-rates is nonlinear.

<p>Shown is a scatterplot of model PN and model ORN firing-rates associated with a typical glomerulus in our model. Spike rates were measured during the epoch during which PN firing-rates peak following odor presentation. Note that, qualitatively similar to experiment <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002622#pcbi.1002622-Bhandawat2" target="_blank">[20]</a>, the model PN firing-rates saturate for relatively small values of ORN firing-rates.