Mice are able to sense volatile cues that warn them from danger. This detection is mostly taking place in the Grueneberg ganglion (GG) olfactory subsystem. GG neurons can detect alarm pheromones released by stressed conspecifics to signal danger as well as kairomones involuntarily released in predator biological secretions allowing an interspecies danger communication. The precise signalling pathways occurring in GG neurons are still unclear. We thus focused on the investigation of the different cascade elements in a new in vitro model. We first incorporated the three bitter taste receptors (TAS2Rs) present in GG neurons in a heterologous system using HEK 293 cells and we demonstrated that we could mimic neuronal responses after stimulation with biological secretions from predators. We identified by calcium imaging experiments that the biological secretions from the skunk (Mephitis mephitis) are a potent source of kairomones. Indeed they can activate these TAS2R-expressing cells as well as GG neurons and induce fear-related behaviours in mice. We can thus correlate the fear signalling observed in vivo to ex vivo (GG tissue slices) and to in vitro experiments. We investigated further the other cascade elements such as the cyclic nucleotide-gated channel type A3 (CNGA3), essential for the entry of Ca²⁺, which induces the depolarization of the membrane after the detection of alerting molecules. The use of pharmacological inhibitors such as L-Cis diltiazem allowed to verify its implication ex vivo. We then additionally transfected CNGA3 in our TAS2Rs in vitro model. We could demonstrate its membrane expression by immunocytochemistry and verify its functionality pharmacologically by calcium imaging using 8 Br-cGMP and a series of inhibitors. We thus managed to “upgrade” our in vitro model as with TAS2Rs and CNGA3 co-expression we observed a synergistic effect after stimulation by predator danger cues. This “fear-vitro” model can now be used to identify new alerting cues.