Fig. 3

Volatility of danger signals is critical to induce fear behaviours in mice in a GG-dependent manner. a GG ligands and bitter tastants sorted according to their volatility. GG ligands are indicated in blue and bitter tastants in green. The abbreviation, molecular formula and molecular weight (M/W) are indicated for each compound. The volatility is estimated from their respective vapour pressures (mmHg at 25 °C) with EPI suite; n.d. not determined. b OMP-GFP mouse phenotyping. Whole-mount fluorescent view of GG regions from a control (Ctrl) and an axotomized (Axo) mouse. c Comparisons between Ctrl and Axo mice for their score of risk assessments and index of freezing time. Cat fur odour (CFO, in red) was used as a GG-independent fear inducer. In b, scale bars = 0.25 mm. In c, data are presented as mean ± SEM of n = 6–10 Ctrl mice and n = 7–8 Axo mice. For behavioural effects, *P < 0.05; **P < 0.01; ***P < 0.001; ns not significant (Wilcoxon paired test). For phenotype comparisons, #P < 0.05; ###P < 0.001; NS not significant (one-tailed Student’s t test or Wilcoxon test)