Olfactory sense

The odor threshold of carbon disulfide is about 1 ppm in air but varies widely depending on individual sensitivity and purity of the carbon disulfide. However, using the sense of smell to detect excessive concentrations of carbon disulfide is unreHable because of the frequent co-presence of hydrogen sulfide that dulls the olfactory sense. 

Sensory receptors that structurally and functionally belong to the G protein coupled receptor superfamily. Olfactory receptors are a large GPCR family with >300 members in human that are expressed in neurons of the nasal olfactory epithelium where they sense mostly volatile olfactory molecule. The overall number of olfactory receptors differs widely between species and an expansion of different recqrtors is in particular obvious in species that depend on their olfactory sense for survival. 

Berghard A., Buck L. and Liman E. (1996). Evidence for distinct signaling mechanisms in two mammalian olfactory sense organs. Proc Natl Acad Sci 93, 2365-2369. 

Schuett, E.B. and Frase, B.A. (2001) Making scents using the olfactory senses for lion enrichment. The Shape of Enrichment. 10, 1-3. 

The mammalian olfactory sense is also being exploited to detect disease. African giant pouched rats can detect tuberculosis in sputum (Holden, 2004)... 

Hansen, L. P., D0ving, K.B., and Jonsson, B. (1987). Migration of farmed adult Atlantic salmon with and without olfactory sense, released on the Norwegian cozst. Journal of Fish Biology 30,713-722. 

This volume can best be understood by considering the olfactory senses of animals. Everyone has witnessed the ability of a dog to use its nose with its superb olfactory sense to detect trace odors. A holy grail of detection science has been to duplicate a dog s nose electronically. Dr. Woodfin s volume tries to assess where the scientific community stands in its search for this holy grail. The authors of this volume are using this chemical sensing approach to detect explosives. Explosives, as used in this context, are defined as materials that concentrate releasable energy controllable or uncontrollable. 

Sarig, Y. (2000) Potential applications of artificial olfactory sensing for quality evaluation of fresh produce. J. Agric. Eng. Res. 77 239-258. 

Cocaine and other local anesthetics abolish not only the sensation of pain, but other special sensations, if they are suitably applied. Here also there is some selection. In the skin, they paralyze first the vasoconstrictor reaction, then progressively the sensations of cold, warmth, touch, tickling, pressure, pain, and joint sense. In the nose, they abolish the olfactory sense. On the tongue, they destroy the taste for bitter substances but have less effect on sweet and sour taste and none on salty taste. When cocaine is applied to the appropriate nerves, it is found that the centrifugal vagus fibers are paralyzed before the centripetal, vasoconstrictor fibers before vasodilator, bronchial constrictors before the dilators, etc. (Sollmann, 1944). 

Valentine J. M. (1931) The olfactory sense of the adult mealworm beetle Tenebrio molitor (LINN). J. Exp. Zool. 58, 165-227. 

Gupta B. P. and Rodrigues V. (1997) atonal is a proneural gene for a subset of olfactory sense organs in Drosophila. Genes to Cell 2, 225-233. 

Gupta B. P., Flores G. V., Baneijee U. and Rodrigues V. (1998) Patterning an epidermal field Drosophila lozenge, a member of the AML- 1/Runt family of transcription factors, specifies olfactory sense organ type in a dose-dependent manner. Dev. Biol. 203, 400-411. 

Reddy G. V., Gupta B., Ray K. and Rodrigues V. (1997) Development of the Drosophila olfactory sense organs utilizes cell-cell interactions as well as lineage. Development 124, 703-712. 

Insect chemosensory organs have been differentially developed for taste and olfactory sensing. The contact and the distant chemosensory sensilla are responsible for nonvolatile and volatile chemical reception, respectively. The CHCs with long carbon chains are non-volatile, and therefore thought to be received by taste sensilla (Ebbs and Amrein, 2007). However, because of their insolubility in water, it was very difficult to obtain response recordings to them from taste sensilla. Success was recently obtained, however, in Drosophila melanogaster, where a male-specific CHC as a sex-pheromone inhibiting male-male courtship was found to stimulate the bitter taste receptor neuron within the... 

Although this book is primarily concerned with creative perfumery, in this chapter we will be looking briefly at the function of smell in nature and the implications that this can have for the work of the perfumer. Smell is the most primitive of the senses, and our response to certain odors is deeply embedded in the subconscious mind. Much of what we know to be true, from our experience as perfumers, can be related to the origins of our olfactory sense and the part that it has played in the evolution of our species. 

Smell, subjective measure of the reaction of a person s olfactory sense to a... 

The standard measurement procedure for odor determination (VDI, 1994) is called olfactometry. It uses the human olfactory sense (Gostelow et al, 2001) for the determination of odor qualities. The human nose is an extremely sensitive odor detector and is used in subjective and objective sensory measurements. The latter expresses the strength of odor in terms of the number of dilutions of odor-free air required to reduce the sample odor to threshold concentration (Gostelow et al, 2001). The threshold concentration is reached when the human nose can just smell the odorous substance. Because every nose has different sensitivity, the standard test procedure involves four people at the same time. Prior to olfactory... 

Hydrogen sulfide is a colorless, flammable gas with important chemical and toxicological properties. It is the product of a number of natural processes, including the decay of sulfur-containing material. Its noxious odor of rotten eggs permits its detection at extremely low concentration (0.02 ppm). Because the olfactory sense is dulled by its action, however, higher concentrations may be tolerated, and the lethal concentration of 100 ppm may be exceeded. Aqueous solutions of the gas were used traditionally as a source of sulfide for the precipitation of metals, but because of the toxicity of H2S, this role has been taken over by other sulfur-containing compounds such as thioacetamide. 

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