Once upon a time we had no idea how odor molecules activated the olfactory nerves in the nose. Various theories were proposed. Shape theory held that activation happened when an odor molecule fit into a suitably shaped receptor protein in a lock-and-key fashion. Vibration theory held an odor receptor is activated by an odor molecule’s specific vibrational frequency.
Everything changed in April, 1991 with Linda Buck and Richard Axel’s paper in Cell. They discovered mammalian genes that code for G protein-coupled receptors (GCPRs) expressed in the sensory neurons of the nose. GCPRs are a type of cell surface receptor found throughout the body; they are activated by the shape and electrical charge of an incoming molecule (a hormone, say, or a neurotransmitter). This discovery, which later won a Nobel Prize, confirmed the shape theory of olfaction.
The other big news was the sheer number of genes coding for olfactory receptors (ORs). We now know that humans have ~400 GCPRs that are expressed in the sensory neurons of the nose. It has taken much longer than many of us expected to sort out which molecules activate which ORs, much less how they code for specific odor perceptions.
In the meantime, a few researchers refuse to let vibration theory die. The holdouts propose elaborate biophysical mechanisms—such as the quantum physics phenomenon of inelastic electron tunneling (IET)—by which vibrations could activate ORs. These theories have had little impact on the field but their proponents refuse to give up.
Now, out of left field, a guy named Kenneth Willeford proposes a new twist: that inelastic electron tunneling results in “fluorescence luminescence with radiative emission of multiple photons” and that combinations of these twinkly light bursts cause odor-specific activation of the olfactory nerves. Willeford’s hypothesis adds new layers to vibration theory, including “the Förster resonance mechanism and the Dexter exchange mechanism”—things that are beyond my ken.
What motivates Willeford’s new bells and whistles? He believes that when odor molecules flood the nose they create vast numbers of inelastic electron tunneling events. Willeford wants to know how the nervous system extracts an odor-specific code from this biophysiological noise. In other words, he asks how temporal summation of individual OR activations creates a sensation. Not a crazy question. But to answer it he makes an awful lot of assumptions about the connectivity and functioning of the olfactory nervous system which strike me as thinly justified. To his credit, Willeford proposes specific ways his theory could be tested.
So who is this guy? He’s a practicing physician in Supply, North Carolina a small town near Cape Fear (a couple of miles south of Green Swamp Preserve). His specialty is anesthesiology, and he has a clinical practice in Interventional Pain Management. He obtained his MD at George Washington University School of Medicine in 1988. Willeford holds a number of medical-related patents.
According to this website, Willeford has a degree in physics and “started his career as a research physicist” before going to med school. That would explain his fluency in quantum biophysics.
Along with his wife Carly Willeford (who holds a Doctorate of Nursing Practice), he published a book that analyzes ancient calendar practices to confirm at least one prediction of the Biblical prophet Isaiah.
How he came to be interested in the biophysiology of olfaction is anyone’s guess.
Kenneth Willeford. (2023). The luminescence hypothesis of olfaction. Sensors 23:1333.
Seems to me that refusal to let it go vibration theory research is now compensated by refusal to get fragrance samples to review...so it was announced in the social medias... as per the shinning nose theory...very christmasy Rudolf!
It may not be coincidence that Sensors is in MDPI's stable of pay-for-pages open access journals.