I am posting this response from a colleague who has expertise in this field. Good luck with your research!
KV This simple question conjures up a whole host of questions in turn. By "olfactory sensitivity," is it meant: 1. olfactory epithelium or VNO (vomeronasal organ)? 2. quantitative or qualitative? 3. means of measurement? In some studies, electrical current is measured after passing scents across the olfactory epithelum or VNO, but this will vary considerably. In any mammal, e.g. Canis familiaris, this varies by breed, age, sex, and hormone levels. Papers have been published on quantitative levels of scent but little on the qualitative aspects and the variation of olfactory epithelium vs. VNO. For example, in humans, the steroid musks (ca. 15-18 carbons) fall on the very edge of what we can detect but can have profound physiological effects. Can other mammals smell higher molecular weight compounds? More research seems to have been done with insects, as might be expected in government-funded research to control insects by pheromones. Because we are routinely contracted to analyze essential oils and related products by GC/MS from private industry, I have an extensive reprint file on mammalian odors (sometimes we get things like ambergris or civet), including odors of dairy, fish, meat, etc. However, I have almost nothing on the variation of olfaction in vivo across the broader taxa, i.e., mammalian families. However, much work has been done on the molecular reasons for olfaction; the most work has been done with mice and humans, but researchers have documented the number of olfactory receptor genes in gibbons, orangutans, rats, frogs, dolphins, etc. Carl Zimmer had a good summary in Natural History in June 2002: “The genes that make olfactory receptors in living vertebrates all descended from a single ancient gene [probably from a fish that lived ca. 520 million years ago] carried in some common ancestors. The evidence also shows that the evolution of olfactory genes has repeatedly involved duplication of a gene in its entirety, and subsequent mutations that introduce slight differences between the two copies. As the genes changed and multiplied, they grew into a family.” These papers, documenting genes and pseudogenes, would probably be the best approach to actually estimate “sensitivity” across mammals (search “olfactory receptor genes mammals” …Google immediately pulls up a number of papers, and you could probably find more on MedLine, etc.). Further confusing the question is the ability to discern individual compounds in mixtures; this has been demonstrated with pheromones in insects but still needs more study in mammals (similar to our ability to hear a familiar voice at a cocktail party and tune out the rest). A good person to seek further information is Dr. Bruce Kimball at Monell Chemical Senses Center in Philadelphia: http://www.monell.org/faculty/people/bruce_kimball and/or Dr. Amos B. Smith, III: http://www.monell.org/faculty/people/smith check out the home page of Monell: http://www.monell.org/ Art P.S. the first ones, in 1991, to discover genes for olfactory receptors were Richard Axel: http://neuroscience.columbia.edu/department/index.php?ID=27&bio=8 and Linda Buck: http://nobelprize.org/nobel_prizes/medicine/laureates/2004/buck-cv.html They won the Nobel Prize in Physiology or Medicine in 2004! “A few months in the laboratory can save a few hours in the library.” Frank Westheimer's Law "Unvouchered plant research is about as memorable as Whistler's father." Art Tucker's Law _____________________ Dr. Arthur O. Tucker Dept. of Agriculture & Natural Resources 1200 N. Dupont Highway Delaware State University Dover, DE 19901-2277 FAX=302-857-6455 http://herbarium.desu.edu/page17/page22/page22.html DOV Herbarium= http://herbarium.desu.edu DHGMA= http://www.delaware-herb.org On Thu, Dec 2, 2010 at 12:32 PM, R K <podocop...@yahoo.com> wrote: > Would someone be > able to recommend a survey paper on olfactory sensitivity in different > mammals? I'm > interested in the differences in sensitivity across taxa--whether > certain species are more focused on certain elements of the olfactory > environment. > > I realize this is something of a naive question, > but I know very little about the scent landscape and how mammals live > in it, so any guidance whatsoever would be most appreciated. Thanks > much to all. > > > > > > > > -- Kevina Vulinec, PhD, Department of Agriculture and Natural Resources, Delaware State University, Dover, Delaware 19901-2277, (302) 857-6457 Fax: (302) 857-6455, kvuli...@desu.edu
