Olfactory receptors interact with odorant molecules in the nose, to initiate a neuronal response that triggers the perception of a smell. The olfactory receptor proteins are members of a large family of G-protein-coupled receptors (GPCR) arising from single coding-exon genes. Olfactory receptors share a 7-transmembrane domain structure with many neurotransmitters and hormone receptors and are responsible for the recognition and G protein-mediated transduction of odorant signals.[5]
Variation in the OR6A2 gene has been identified as a likely cause of why some people enjoy the smell and taste of coriander (also known as cilantro) while others are extremely repulsed by it.[6] Depending on ancestry, between 3% and 21% of the population report disliking coriander: 21% for East Asians, 17% for Caucasians, 14% for those of African descent, 7% for South Asians, 4% for Hispanics, and 3% for Middle Eastern subjects.[7] Some associate it with an intensely unpleasant taste, including a combination of soap and vomit, or say that it is similar to the foul smelling odor emitted by stinkbugs. This is suggested to be due to the presence of aldehyde chemicals,[8] which may be present in soap, various detergents, coriander, and several species of stinkbugs.[citation needed]