Fig. 1

Olfactory discrimination deficiency in Tbr1^+/− mice. a Flow chart of our odor preference test (upper panel) and olfactory sensation-habituation-dishabituation test (lower panel). b The results of the preference test. Wild-type (WT) and Tbr1^+/− mice spend similar amounts of time sniffing limonene (L) and 2-heptanol (H). c The results of olfactory sensation. Sniffing time of limonene by WT and Tbr1^+/− mice is comparable in the first trial of our olfactory discrimination test. d The results of trials 1–5 of the sensation-habituation-dishabituation test. Olfactory habituation to limonene (L) is similar between WT and Tbr1^+/− mice. But Tbr1^+/− mice exhibit an olfactory discrimination deficiency in distinguishing 2-heptanol and limonene in trial 6. e Sniffing time of limonene (L) and 2-heptanol (H) by WT and Tbr1^+/− mice during trial 6. f Odor preference index from trials 1 and 6. The equations to calculate the odor preference index are indicated. Data are presented as mean plus SEM in (b), (c), (d), and (f). Data from individual mice are also indicated in (b), (c), (e), and (f). **p < 0.01; ***p < 0.001