Fig. 4.
Responses of receptors to the panel of most effective odorants. (A) Responses of each receptor to the panel of 18 odorants, each tested at a 10−4 dilution. Each value represents the mean response during a 0.5-s odor stimulation period. Spontaneous activity and response to solvent alone have been subtracted (6 ≤ n ≤10). (B) Mapping of the most effective odorants (large dots) and the other 461 odorants (small gray dots). Shown are the first three principal components (PCs) of the 32-dimensional odor space of Haddad et al. (31). Physicochemical descriptors were normalized. Variances explained by PC1, PC2, and PC3 are 17%, 13%, and 12%, respectively.