Histamine is however one of the mast cell mediators implicated in the activation of afferent-expressed TRPV1[19] and post stress treatment with the selective TRPV-1 antagonist SB-705498 reversed visceral hypersensitivity in the MS model.[15] Thus, we considered MS a suitable model to evaluate the possible use of H1R antagonists in the treatment of stress-induced IBS-like phenotypical changes. The gene discussed is HRH1; the disease is irritable bowel syndrome.