Sometimes a new idea comes out of the mouth of babes, snakes, and scientists. A study published last week online in advance of the print edition in Oxford Academic Chemical Senses finds that smell may begin with the tongue rather than the brain. One of the study’s authors, Mehmet Hakan Ozdener, MD, PhD, MPH, became intrigued with the idea when his adolescent son asked whether snakes stick their tongues out in order to smell.
A current model of taste and smell shows two genetically different receptor systems located in anatomically distinct locations that send signals to different targets. While the two are known to intertwine to form the perception of flavor, scientists thought that the first merger occurred in the insular cortex – a part of the cerebral cortex in the brain. The insulae are believed to play a role in functions that include perception, motor control, self-awareness, cognitive functioning and interpersonal experience.
The abstract of this new study states: “Here we report that olfactory receptors are functionally expressed in taste papillae…The results provide the first direct evidence of the presence of functional olfactory receptors in mammalian taste cells. Our results also demonstrate that the initial integration of gustatory and olfactory information may occur as early as the taste receptor cells.” (1) Other experiments confirm that smell and taste receptors may be found within the same cell.
There are 400 different types of functional human olfactory receptors and scientists do not know what molecules activate the vast majority of them. While fascinating, this study alone does not answer that question or have a practical application other than to advance knowledge that will lead to other studies.
That’s the beauty of science. It’s a living body of changing knowledge. One layer builds on another. The more we understand about how things work, the more options we have for enhancing our lives. It’s good to remind ourselves of that occasionally.
Believing science has become a battle cry among those who want to stand firm on what we currently know. There’s a danger in that because tomorrow we will know more and that may mean that what we know today is no longer supported by the evidence. It also makes science sound like a restrictive rule book. Who wants to learn a bunch of rules? Certainly not bright minds that can imagine big ideas.
Instead of believing science, I’d rather we love it! And while we’re loving it, let’s be curious. Curiosity leads to advancement. Questioning is good. Skepticism can play a valuable role. Allowing our understanding to shift and change does not threaten our way of life. It has the potential to vastly improve it.
But don’t take that from me, take it from the mouth of a scientist: “I have no special talents. I am only passionately curious.” – Albert Einstein.