Love is in the air everywhere I look around.
Love is in the air every sight and every sound.
– John Paul Young
John Paul Young’s lyrics attribute sight and sound as the two main vehicles of love and in musical theater that may be true, but he has forgotten the important sense of smell and its effects on love. Last week, on the day after Valentine’s Day, our holiday dedicated to romantic love, I attended a lecture by Tim Holy (Washington University) entitled, “Pheromones: The Science of Love”. By way of definition, pheromones are chemicals released into the environment by an animal, especially a mammal or an insect, affecting the behavior or physiology of others of its species. The proximity to Valentine’s Day may have led Dr. Holy to take some latitudes in his introduction, but the overall fundamentals of his talk seemed solid enough.
He quickly brushed past the effects of pheromones in humans, with an ‘I don’t know’ and did speak about pheromones and their effects in insects, but the focus of his research is pheromones in mice. He described an experiment where he stacked two cages. In each cage he placed one mouse. In all of the possible combinations, only when he place a female mouse in the upper cage and a male mouse in the lower cage did he obtain results that were positive for transmission of pheromones. He measured this transmission using an electron microscope that was used to examine the olfactory nerves in the male mouse’s nasal cavity.
I suspect that this examination did not go all that well for the male mouse. I am reminded of a Garrison Keillor story that describes an analogues situation in the Minnesota woods. It is fall and there is a certain crispness to the air. The male deer, the buck is in rut. As he prances through the woods his nostrils are filled with the scent of female does in heat. Unexpectedly their scent is soon masked by the smell of cigars and coffee. The muzzle flash of the hunter’s gun soon puts an end to all of this young buck’s thoughts of love.
But I digress, let’s get back to the science. Under the electron microscope Holy has identified 17 different types of olfactory nerves in these mice. Only in the girl on top and boy on the bottom situation does one of these 17 nerve types light-up. Holy hypothesizes that its excitation is due to pheromones. In fairness to Dr. Holy, I’m not sure that I have adequately communicated his results. If so, then I apologize. Anyway, it was an interesting lecture.