Olfactory sensitivity

Odors are characterized by quaUty and intensity. Descriptive quaUties such as sour, sweet, pungent, fishy, and spicy are commonly used. Intensity is deterrnined by how much the concentration of the odoriferous substance exceeds its detection threshold (the concentration at which most people can detect an odor). Odor intensity is approximately proportional to the logarithm of the concentration. However, several factors affect the abiUty of an individual to detect an odor the sensitivity of a subject s olfactory system, the presence of other masking odors, and olfactory fatigue (ie, reduced olfactory sensitivity during continued exposure to the odorous substance). In addition, the average person s sensitivity to odor decreases with age. 

The production of a female-influencing secretion from the chin gland of male Plethodontid salamander (P. jordani) points to a similar extension of function by the acquisition of female olfactory sensitivity to an intercellular signal protein. Female receptivity is enhanced by a male cytokine-like compound of the interleukin-6 family, in its released form. Rollman et al. (1999) note that pheromonal activity is a previously unrecognised function for cytokines. 

Dorries K.M., Adkins-Regan E. and Halpem B.P. (1995). Olfactory sensitivity to the pheromone, androstenone, is sexually dimorphic in the pig. Physiol Behav 57, 255-259. 

Wysocki C.J., Zeng C. and Preti G. (1999). Specific anosmia and olfactory sensitivity to 3-methyl-2-hexanoic acid a major component of human axillary odor. Chem Senses 25, 652 (abs. 330). 

Fig. 6.1 Different strains of mice detect different concentrations of urinary odours of conspecifics with BALB/c>129/Sl>C57BL/6. Presented are the mean durations ( SEM) that mice investigated water and three sequential 2-min presentations of the same concentration of urine from one of the other strains at (A) 10 2, (B) 10 3 and (C) 10-4 concentrations. Immediatelyafter the presentation of Urine A, mice were exposed to a novel urine B (the other foreign strain) at the same concentration.(Reprinted from Neuroscience, 118, Lee, Emsley, Brown, and Hagg, T. Marked differences in olfactory sensitivity and apparent speed of forebrain neuroblast migration in three inbred strains of mice. 263-270, Copyright (2006), with permission from Elsevier)...

Lee, A.W., Emsley, J.G., Brown, R.E. and Hagg, T. (2003) Marked differences in olfactory sensitivity and apparent speed of forebrain neuroblast migration in three inbred strains of mice. Neurosci. 118,263-270. 

Laska, M., Seibt, A. and Weber, A. (2000) Microsomatic primates revisited olfactory sensitivity in the squirrel monkey. Chem. Sens. 25, 47-53. 

Doty, R.L. and Ferguson-Segall, M. (1989) Influence of adult castration on the olfactory sensitivity of the male rat a signal detection analysis. Behav. Neurosci. 103, 691-694. 

Kocsis M, Hanson A (2000) Biochemical evidence for two novel enzymes in the biosynthesis of 3-dimethylsulfoniopropionate in Spartina altemiflora. Plant Physiol 123 1153-1161 Kocsis M, Nolte K, Rhoades D, Shen T-L, Gage D, Hanson A (1998) Dimethylsulfoniopropionate biosynthesis in Spartina altemiflora. Plant Physiol 117 273-281 Kowalewsky S, Dambach M, Bjorn M, Dehnhardt G (2006) High olfactory sensitivity for dimethyl sulphide in harbour seals. Biol Lett 2 106-109 Lamb C, Dixon R (1997) The oxidative burst in plant disease resistance. Annu Rev Plant Physiol Mol Biol 48 251-275... 

Olfactory sensitivity for one individual varies about factor three due to climatological, physiological, environmental reaons etc. The sensory sensitivity also varies from odorant to odorant. So it is difficult to select a panel with a sensitivity distribution similar to that of the population. The preferred method in the United Kingdom for screening panelists uses the actual odor to be tested as a key component. In France selection is carried out on the basis of the threshold for five standard odorants. In Germany a normal sense of smell is requested of persons between the age of 18 and 50 years, in the Netherlands no exact specifications are given. Anyway, an extreme clustering around the mean or towards the extremes has to be avoided. 

In view of the intraindividual variation in olfactory sensitivity, which may be quite considerable, a panel of six subjects would be the absolute minimum. 

L. P. Waggoner. Canine Olfactory Sensitivity and Detection Odor Signatures for Mines/UXO, Testing Support for Tuft s Medical School E-Nose, and Fate Effects Team Participation , Final Report for MDA972-97-1-0026, Defense Advance Research Projects Agency, 2002. 

The most celebrated mammalian olfactory detector is the dog s nose. As a predator, the dog locates its prey by air scenting (following a gradient of airborne odors) and tracking. Practitioners are familiar with the extreme olfactory sensitivity of the dog. The detection threshold for butyric acid has been determined as 9 x 10 molecules/cm air (Neuhaus, 1953). Considering that... 

Odor thresholds in humans appear to be more influenced by the environment than genetics. The detection thresholds for acetic acid, isobutyric acid, and cyclohexanone varied as much in monozygotic twins as in fraternal twins. Instead, smoking and diabetes were related to lower olfactory sensitivity, and body fatness and alcohol consumption to greater sensitivity to the latter two compounds (Hubert eta/., 1980). 

Bjerselius, R. and Olsen, K. H. (1993). A study of the olfactory sensitivity of the crucian carp (Carassius carassius) and goldfish (Carassius auratus) to 17a,20 8-dihydroxy-4-pregnen-3-one. Chemical Senses 18,427-436. 

Dorries, K. M., Adkins-Regan, E., and Halpern, B. P. (1991). Sex difference in olfactory sensitivity to the boar chemosignal, androstenone, in the domestic pig. AnimalBehaviour 42,403-411. 

Dpving, K., Selset, B., and Thommsen, R. (1980). Olfactory sensitivity to bile acids in salmonid fishes. ActaPhysiologicaScandinavica 108,123-131. 

Hubert, H. B., Eabsitz, R. R., Eeinleib, M. and Brown, K. S. (1980). Olfactory sensitivity in humans genetic versus environmental control. SciencelOB, 607-609. 

Johnsen, P. B., Zhou, H., and Adams, M. A. (1988). Olfactory sensitivity of the herbivorous grass carp, Ctenopharyngodon idella, to amino zdds. Journal of Fish Biology 33,127-134. 

Kasumyan, A. 0. (1994). Olfactory sensitivity of the sturgeon to free amino acids. Biophysics 39, 509-522. 

Laing, D. G. (1975). A comparative study of the olfactory sensitivity of humans and rats. 

Mair, R. G., Bouffard, J. A., Engen, T., and Morton, T. H. (1978). Olfactory, sensitivity during the menstrual cycle. Sensory Processes 2,90-98. 

Marshall, D. A. and Moulton, D. G. (1981). Olfactory sensitivity to a-ionone in humans and dogs. Chemical Senses 6,53-61. 

Smith, S. A. and Paselk, R. A. (1986). Olfactory sensitivity of the turkey vulture Cathartes aura) to three carrion-associated odors Aufe 103,586-592. 

Snyder, G. K. and Peterson, D. T. (1979). Olfactory sensitivity in the black-billed magpie and in the pigeon. ComparativeBiochemistry andPhysiologyA 62,921-925. 

Soffie, M. and Lamberty, Y. (1988). Scopolamine effects on juvenile conspecific recognition in rats possible interaction with olfactory sensitivity. BehavioralProcesses 17,181-190. 

Sorensen, P. W., Stacey, N. E., and Kara, T. J. (1990b). Acute olfactory sensitivity and specificity of mature male goldfish to water borne androgenic steroids a class of inhibitory pheromones. Chemical Senses 15,644. 

Sorensen, P. W., Irvine, I. A. S., Scott, A. P., and Stacey, N. E. (1992). Electrophysiologi-cal measures of olfactory sensitivity suggest that goldfish and other fish use species-specific mixtures of hormones and their metabolites as pheromones. In Chemical Signals in Vertebrates, vol. 6, ed. R. L. Doty and D. Miiller-Schwarze, pp. 357-354. New York Plenum. 

It has been suggested that these anosmias refer to a primary odor classification. These olfactory sensitivity differences could potentially contribute significant differences in flavor perception among individuals for a given product. 

Nishino, C. and Usui, K. (1985). Olfactory sensitivity of Periplaneta cockroaches to... 

Although odor (essence I is an important part of flavor sensitivity, there arc numerous inedible consumer products where olfactory sensitivity is the principal concern. In addition to perfumes, soaps, hair sprays, and other cosmetics, odor is important to the acceptability of laundry and cleaning products, polishes and waxes, and decorative materials. Deodorizing agents also fall within this general sphere of interest. 

Sorensen, P. W. and Scott, A. P., The evolution of hormonal sex pheromones in teleost fish. Poor correlation between the pattern of steroid release by goldfish and olfactory sensitivity suggests that these cues evolved as a result of chemical spying rather than signal specialization, ActaScand. Physiol., 152, 191, 1994. 

Van der Goes van Naters W. M., Den Otter C. J. and Maes F. W. (1998) Olfactory sensitivity in tsetse flies a daily rhythm. Chem. Senses 23, 351-357. 

Getz, W.M. and Smith, K.B. (1987). Olfactory sensitivity and discrimination of mixtures in the honeybee Apis mellifera. J. Comp. Physiol. A, 160, 239-245. 

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