(A, B) In a go/no go operant conditioning task, M71 transgenic mice fail to discriminate acetophenone from mineral oil (left panels). In contrast, M71 transgenic mice readily discriminate other pairs of odorants (ethyl acetate vs. mineral oil, citronellol, or carvone, right panels). (A) Original results reported in Fleischmann et al. (2008). (B) Repeat experiment with an additional cohort of mice. Thin lines: learning curves for individual mice. Thick lines: averaged learning curves. Error bars: 95% CI of the mean. (C) Sniff adaptation: schematic of the experimental configuration. (D) Example sniff traces during first 3 (1st, 2nd, and 3rd) presentations of hexanone (shaded area) from a control mouse. Lighter colored traces signify later presentations. ‘FV’ trace shows opening of final valve directing odorized air to the mouse, ‘flow’ trace shows the output from the olfactometer, and ‘PID’ trace shows signal evoked by odorized air from a photo-ionization detector. (E) Example moving averages of instantaneous sniff frequency during first 3 presentations of hexanone (window = 500 ms, plotted against leading edge). Black traces: controls, red traces: M71 transgenic mice. (F, G) Mean instantaneous sniff frequency responses to first vs. the average of the 2nd and 3rd presentation of an odor for control (black, F) and M71 transgenic (red, G) mice. Pooled non-acetophenone odorants: hexanone, ethyl acetate, heptanal, and an odor mixture. Lighter colors: individual trials, thick lines: averages. Error bars: SD. Black dotted lines on the M71 plots show the means for the corresponding data from controls.