Figure 5.

Responses to monomolecular odors are sparse in MB. A, Proportion (prop.) of KCs responding to a variety of different odors. Black points show sparseness values from individual animals (n = 8 flies); gray circles show the grand mean. B, Mean sparseness values as a function of total ORN activity [ORN data from Hallem and Carlson (2006)] for each odor. Some KC responses shown in A are not plotted since ORN data do not exist for these odors. The slope of the fit is significantly different from zero (p = 0.0001) (see Results).