I just spent some time reviewing posts that mentioned the human VNO and was delighted to find that so many people on this Forum are well informed about its reported non-existance. I will not involve myself in fruitless discussions about a non-existant organ–as I have innefectively done so in other Forums where product marketing prevails. Instead, here are a few of the latest research reports that attest to the biological facts:
Olfactory neurons expressing transient receptor potential channel M5 (TRPM5) are involved in sensing semiochemicals. Weihong Lin, Robert Margolskee, Gerald Donnert, Stefan W. Hell, and Diego Restrepo PNAS. 2007; 104(7): p. 2471-2476 http://www.pnas.org/cgi/content/abst…4/7/2471?ct=ct
“Though some humans exhibit a small patch inside their nose resembling the vomeronasal organ in rats that detects pheromones, it appears to be vestigial, with no nerve connection to the brain.”
Knecht M, Lundstrom JN, Witt M, Huttenbrink KB, Heilmann S, Hummel T.Assessment of olfactory function and androstenone odor thresholds in humans with or without functional occlusion of the vomeronasal duct. Behav Neurosci. 2003 Dec; 117(6): 1135-41.
KEY INDICATION: The human vomeronasal duct, and therefore, the human VNO does not play a major role in sensitivity toward odorants or the perception of a putative human pheromone.
BM Pause
Is the human skin a pheromone-producing organ?
J Cosmet Dermatol 1 Dec 2004 3(4): p. 223. HighWire Press – Medline Abstract
“It has been suggested that humans might have a special organ within their nose that can transmit such chemosensory information. However, the evidence for this organ is highly questionable. In any case, the main olfactory system is a highly diverse system, capable of transmitting pheromonal information.”
Brennan PA, Zufall F. Pheromonal communication in vertebrates. Nature. 2006 Nov 16;444(7117):308-15.
“More problematic for advocates of the existence of a human VNO are the consistent failure to find vomeronasal nerves projecting to the brain and the failure to find an AOB in adult humans.” (p. 313)
I’ve read various reports and posts stating that the VNO is pretty much nonexistent now. However if the organ specifically designed for receiving and interpreting pheromone signals is obsolete, then how are my pheromones working?, what mechanism has that function been transferred to?
The evolved neurophysiological mechanism is the biological core of mammalian reproduction: the gonadotropin releasing hormone (GnRH) pulse generator in the hypothalamus of most, if not all, vertebrates. It has been the focus of my research since the early 90’s, which is the same time promotion of the human VNO and “Sixth Sense” began, and began to be discredited among members of the scientific community.
The powerpoint version of my presentation of this publication to the Society for the Scientific Study of Sexuality is here:
Ego Wall Society for the Scientific Study of Sexuality ? scentoferos
And I have loaded four 5 minute video clips to youtube from my presentation of the same material to non-scientists at Mensa, the high IQ society.
But, as anyone will see who attempts to read and digest the information, there are levels of complexity involved that may preclude understanding (though the video clips are easy to understand). Even with the results of our experiment made publicly available, http://posters.f1000.com/Image?posterID=1387&type=poster
most people will continue to be plagued by representations of the human VNO as controversial. There is no controversy.
I think it would be great if every time someone on this Forum sees the human VNO mentioned in advertisements for products, they report it. That’s one way to rid ourselves of a bastardized concept, and to move forward with the science of how pheromones really do affect behavior.
Keep in mind that article was from 1994. Back then they were still researching and trying to prove or disprove the VNO’s function or lack of it in humans.
Just because it has been ruled out as functional doesnt mean pheromones do not work in humans. It indicates what we already know. They work differently in humans then in other mammals.
Of course human pheromones work, as shown in our results using a mixture of androstenol and androsterone. But they work in the same way as in other mammals. For example, androstenol is known to cause changes in levels of luteinizing hormone (LH) in women, and the LH response to pheromones of the opposite sex is the most measurable response known to exist across species from yeasts to humans. And, even without demonstrable changes in behavior, mammalian pheromones, including human pheromones, are known to cause changes in LH.
For comparison to the misinformation about the human VNO and human pheromones that started to be propagated in the early 1990’s, my first presentation to other scientists was titled: Luteinizing hormone (LH): the link between sex and the sense of smell? The question mark in the title indicated I wasn’t sure. It’s been 20 years, and now I am sure.
LH is the link between sex and the sense of smell. No sixth sense, human VNO, or anything other than what has been learned through decades of progress in neuroscience. Recent focus on epigenetic influences on hormones and behavior will begin to cause more people to realize the importance of pheromones in all species. How could they not be equally important to the development of human sexual preferences?