The major objective of this research is to understand the molecular, cellular and systems-level mechanisms responsible for the detection and discrimination of odorant mixtures and their components. This includes gaining an understanding of the effects of mixtures interactions on coding in the nervous system as well as the behavioral discrimination of odors and intensity. Experiments are conducted using the spiny lobster and a set of 7 odorant to examine the effects of mixture interactions on nerve cell activity and behavioral responses using conditioning techniques to examine discrimination of odorant. These studies will contribute to a better understanding of the events that underlie the perception of odorant and how a relatively simple nervous system encodes this sensory information and uses it to control behavior to chemical substances.