Olfactory discrimination ability of CD-1 mice for aliphatic aldehydes as a function of stimulus concentration
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Using an operant conditioning paradigm, we tested the ability of CD-1 mice to discriminate between members of a homologous series of aliphatic aldehydes presented at four different concentrations. We found that the mice were clearly capable of discriminating between all odorant pairs when stimuli were presented at concentrations of 1, 0.01, and 0.001 ppm (corresponding to four, two, and one log unit above the highest individual detection threshold) with no significant difference in performance between these concentrations. In contrast, the animals generally failed to discriminate above chance level when stimuli were presented at 0.0001 ppm (corresponding to the highest individual detection threshold) although stimuli were clearly detectable. Further, we found a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length. These findings suggest that an increase in stimulus concentration of only one log unit above detection threshold appears to be sufficient for recruitment of additional subpopulations of odorant receptors to allow for qualitative recognition of aliphatic aldehydes.
KeywordsOlfactory discrimination Aliphatic aldehydes Stimulus concentration CD-1 mice
GMS is supported by NIH grant (5 R01 DC00086-38) and the Human Brain Project. The experiments reported here comply with the Guide for the Care and Use of Laboratory Animals (National Institutes of Health Publication no. 86-23, revised 1985) and were performed according to a protocol approved by the Yale University Institutional Animal Care and Use Committee.
- Doty RL, Laing DG (2003) Psychophysical measurement of human olfactory function, including odorant mixture assessment. In: Doty RL (ed) Handbook of olfaction and gustation, 2nd edn. Marcel Dekker, New York, pp 203–228Google Scholar
- Wilson DA, Stevenson RJ (2006) The relationship between stimulus intensity and perceptual quality. In: Wilson DA, Stevenson RJ (eds) Learning to smell. Johns Hopkins University Press, Baltimore, pp 64–75Google Scholar