Fig. 1.

A number of TAAR ligands and other odorants elicit innate attraction or aversion. (A) Individual mouse TAARs were expressed in HEK293 cells and tested for responses to different odorants. Shown here are 19 of 24 odorants, all amines, which activated one or more TAARs (see Materials and Methods for full names). Colored boxes indicate EC₅₀ values. Individual odorants activated one to six TAARs. (B and C) The olfactory preference test was used to assess the ability of 19 TAAR ligands (B) and 54 other odorants (C) to elicit attractive or aversive behavior. The test measures the time an animal spends investigating filter paper containing odorant or water during a 3-min period. Odorant abbreviations are shown at left (see Materials and Methods for full names). Bars indicate mean investigation time and error bars show SEM (n = 5–10 animals/odorant or water). Asterisks indicate responses significantly different from water (unpaired t test; two-tailed): *P < 0.05; **P < 0.01; ***P < 0.001. Bars are colored to indicate aversion (red), attraction (blue), or a neutral response (gray). Images of mice displaying aversive and attractive responses to filter paper (pseudocolored in red or blue) are seen above in B.