The Database of Odor Responses (DoOR): a Functional Atlas of All Available Odor Responses

Odors are recognized by a large family of odor receptors. Each receptor cell expresses one or a few receptor proteins, which give that cell a specific odor response profile. This profile can be represented by a mathematical function.

When we smell, most chemicals stimulate more than 1 odor receptor cell type. The result is that each odor elicits an activity pattern across an array of odor receptor cells. Population coding enables the brain to recognize and remember thousands or maybe millions of different odors with a limited number of receptor types (approximately 350 in humans and about 60 in fruit flies).

The recent paper “Integrating Heterogeneous Odor Response Data into a Common Response Model: A DoOR to the Complete Olfactome” (published September 2010 in Chemical Senses) reports on the creation of a functional atlas of odor responses for not only odor receptors but also the olfactory glomeruli of the fruit fly.

The project is important for two reasons:

  • The functional atlas represents a consensus data set combining all available data that can serve as a standard reference for the sense of smell in fruit flies. Since the odor response profiles are based on many studies they are statistically more reliable than any single study.
  • The computer software tools test an approach for mapping different data sets onto each other.

The team developed a software platform that allows the extraction of odor response profiles across chemicals for individual receptors or the extraction of the entire combinatorial response pattern elicited by a given chemical. The software is an open source R-package and can be downloaded from the DoOR website. The download also includes the fruit fly data.

Note: R-packages are written in the R programming language and and must be run in the R software environment for statistical computing and graphics. The software is all open source and freely available through the R Project for Statistical Computing website.