One of the chemosensory systems in the nose of vertebrates is called the vomeronasal system. It is sometimes used for detecting pheromones in the environment, and in some reptiles it also is essential for prey detection. In contrast to the regular sense of smell, very little is known about how the relevant chemical molecules trigger the intracellular response that leads to a nerve signal from the vomeronasal organ. This step, called transduction, is a very active area of chemosensory research using modern biochemical approaches. This project uses the garter snake as a model system having a high sensitivity to a chemoattractant molecule purified from earthworms, which are a favorite prey item. Biochemical techniques are used to study how intracellular and extracellular levels of calcium ion may depend on a pathway involving a compound known as IP3 (inositol triphosphate). IP3 is known in other signaling pathways to mobilize calcium, and this project will test how it works in the vomeronasal system. Results will be important for clarifying chemosensory transduction in this system that is ecologically important for detecting food as well as mates, and the work also will involve high school students in a research experience.
