Traitement des mélanges par le système trigéminal
The trigeminal system – along with smell and taste – is a chemical sense that allows the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack knowledge of the trigeminal processing of mixtures. We therefore investigated trigeminal perception using mixtures of three relatively receptor specific agonists (eucalyptol, TRPM8 agonist; cinnamaldehyde, TRPA1 agonist and camphor, TRPV1 agonist) together with one control odor (phenyl ethyl alcohol or PEA) in different proportions to determine basic dimensions of trigeminal perception. Four main dimensions were proven relevant to trigeminal perception: intensity, warmth sensation, cold sensation and pain sensation. Subsequently, we used these dimensions to investigate perception of mixtures and combinations of trigeminal stimuli using different concentrations of a cooling stimulus (eucalyptol) with a stimulus which evokes warmth perception (cinnamaldehyde). Results showed mixtures generally yielded higher ratings than combinations on the trigeminal dimensions “intensity”, “warm” and “painful” whereas combinations yielded higher ratings than mixtures on the trigeminal dimension “cold”.  These results suggest dimension specific interactions in the perception of trigeminal mixtures. For the mixtures we used, we reach the conclusion of additivity for the dimensions “intensity”, “warm” and “painful”; we observed suppression of the cold perception of both stimuli in mixtures suggesting particular interactions which may take place on peripheral or central levels.
Trigeminal system Binary mixtures Smell Chemosensory perception