Innate liking and disgust reactions elicited by intraoral capsaicin in male mice.

This article focuses on investigating whether intraoral administration of capsaicin, a chemosomatosensory stimulus, elicits measurable liking and disgust reactions in male mice, as defined by the taste reactivity test—a quantitative method traditionally used to assess affective responses to taste stimuli. The study found that low concentrations of capsaicin induced liking reactions characterized mainly by tongue protrusions, while medium to high concentrations elicited various disgust reactions, including gape and forelimb flail, similar in pattern to those induced by bitter and sour tastants. These findings suggest that orofacial and bodily reactions associated with liking and disgust are not exclusive to taste stimuli but can also be triggered by chemosomatosensory inputs, providing a novel animal model to study the biological basis of these emotions across sensory modalities. The results have implications for understanding sensory processing in health and disease and may aid in exploring mechanisms underlying oral discomfort and pain syndromes.