Our goal is to use neuroinformatics to help resolve the conflicting findings from which two models of olfactory coding have emerged. One model proposes that very many low-specificity neural responses represent each odorant and the other model suggests that fewer, more specific olfactory receptors bind to particular molecular features and that the combination of these specific responses characterizes each odorant. Since much of the data supporting the low-specificity model has been collected without regard for the exquisite spatial heterogeneity of the olfactory system, it is possible that the differences in conclusions could be resolved if the distinct types of data that are collected by various laboratories were placed into spatial register with one another. To that end, we have been building an archive of the spatial patterns of glomerular responses evoked by a wide range of odorants, and we have been able to test hypotheses regarding strategies of olfactory coding by calculating homologies across glomerular-layer response patterns. To facilitate our analytical task, and to make it feasible for others to place their data in register with this odorant response archive, we propose to continue to develop analytical and visualization software for olfactory bulb data. We also propose to extend this approach to both the olfactory epithelium and olfactory cortex to be able to understand both the initial coding and synthetic levels of the olfactory system. These efforts will be freely available via the web site on which our olfactory activity archive is posted. We propose to improve the site by incorporating meta-data, as well as data from labs using other species and other types of data, such as lesions and neurophysiological data that can be located in space. Finally, the wide range of odorants that we must test to capture a sense of the system also will necessitate the use of an informatics approach to allow us to test hypotheses regarding the complex means by which chemical structure is represented in the system. The combination of these approaches should help resolve the differences between the conflicting models of olfactory coding.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
1R01DC006516-01A1
Application #
6803809
Study Section
Special Emphasis Panel (ZRG1-MDCN-G (55))
Program Officer
Davis, Barry
Project Start
2004-08-15
Project End
2007-06-30
Budget Start
2004-08-15
Budget End
2005-06-30
Support Year
1
Fiscal Year
2004
Total Cost
$262,276
Indirect Cost
Name
University of California Irvine
Department
Other Basic Sciences
Type
Schools of Arts and Sciences
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92697
Falasconi, Matteo; Gutierrez-Galvez, Agustin; Leon, Michael et al. (2012) Cluster analysis of rat olfactory bulb responses to diverse odorants. Chem Senses 37:639-53
Johnson, Brett A; Woo, Cynthia C; Zeng, Yu et al. (2010) Prolonged stimulus exposure reveals prolonged neurobehavioral response patterns. J Comp Neurol 518:1617-29
Johnson, Brett A; Ong, Joan; Leon, Michael (2010) Glomerular activity patterns evoked by natural odor objects in the rat olfactory bulb are related to patterns evoked by major odorant components. J Comp Neurol 518:1542-55
Leon, Michael; Johnson, Brett A (2009) Is there a space-time continuum in olfaction? Cell Mol Life Sci 66:2135-50
Johnson, Brett A; Xu, Zhe; Ali, Sameera S et al. (2009) Spatial representations of odorants in olfactory bulbs of rats and mice: similarities and differences in chemotopic organization. J Comp Neurol 514:658-73
Cleland, Thomas A; Johnson, Brett A; Leon, Michael et al. (2007) Relational representation in the olfactory system. Proc Natl Acad Sci U S A 104:1953-8
Johnson, Brett A; Leon, Michael (2007) Chemotopic odorant coding in a mammalian olfactory system. J Comp Neurol 503:1-34
Ho, Sabrina L; Johnson, Brett A; Chen, Andrew L et al. (2006) Differential responses to branched and unsaturated aliphatic hydrocarbons in the rat olfactory system. J Comp Neurol 499:519-32
Youngentob, Steven L; Johnson, Brett A; Leon, Michael et al. (2006) Predicting odorant quality perceptions from multidimensional scaling of olfactory bulb glomerular activity patterns. Behav Neurosci 120:1337-45
Ho, Sabrina L; Johnson, Brett A; Leon, Michael (2006) Long hydrocarbon chains serve as unique molecular features recognized by ventral glomeruli of the rat olfactory bulb. J Comp Neurol 498:16-30