Abstract
Stimulus intensity is a fundamental perceptual feature in all sensory systems. In olfaction, perceived odor intensity depends on at least two variables: odor concentration; and duration of the odor exposure or adaptation. To examine how neural activity at early stages of the olfactory system represents features relevant to intensity perception, we studied the responses of mitral/tufted cells (MTCs) while manipulating odor concentration and exposure duration. Temporal profiles of MTC responses to odors changed both as a function of concentration and with adaptation. However, despite the complexity of these responses, adaptation and concentration dependencies behaved similarly. These similarities were visualized by principal component analysis of average population responses and were quantified by discriminant analysis in a trial-by-trial manner. The qualitative functional dependencies of neuronal responses paralleled psychophysics results in humans. We suggest that temporal patterns of MTC responses in the olfactory bulb contribute to an internal perceptual variable: odor intensity.
Footnotes
↵1 The authors declare no competing financial interests.
↵3 Y.B.S. was supported by the Leon Levy Foundation and by the Visiting Scientist Program at Janelia Farm Research Campus, Howard Hughes Medical Institute. R.S. and D.R. were supported by the Howard Hughes Medical Institute. The work is partially supported by Grant 8UL1-TR-000043 from the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health to Y.B.S. and by Grant 5R01DC013797 from NIDCD to D.R.
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