Author: Brian H Smith, Arizona State University

Title: Using natural odor "scenes" to help crack the olfactory code

Abstract: The understanding of olfaction is made difficult by the complexity of the physical odor "scene". Studies have shown that natural odors are often mixtures of many chemical components, and the biological signal is embedded in a submixture. Furthermore, odors occur in turbulent air flows that mix a target odor with background odors. It is therefore important to formulate an understanding of how natural odors vary from one encounter to the next, and how animals recognize odors in spite of this variance. More in-depth investigations of odor scene space, including statistics relating to variation and background mixing, will reveal a new depth of richness of neural representations of odors in the brain. Insects such as the fruit fly and honey bee are excellent models for this research because of the accessibility of their central nervous systems, because of their ease of use under controlled laboratory conditions. We also have available a rich understanding of the odor ecology of these species in regard to finding food, mates, places to reproduce and in driving social interactions. The seminar will review how processes from early sensory transduction through plasticity in different levels of processing in the brain, including "decision making", can be best understood in terms of adaptations to challenges presented by the complex statistical structure of the odor scene.