Date of Award


Document Type

Restricted Thesis

Terms of Use

© 2006 Arpiar B. Saunders. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts



First Advisor

Kathleen King Siwicki


Male Drosophila suppress courtship toward virgin females after an unproductive sexual encounter with a mated female. This learned behavior is mediated by pheromones and has been formalized as associative learning in a paradigm called courtship conditioning. To identify the neural machinery responsible, four populations of gustatory receptor neurons (GRNs) were functionally silenced during the male's initial training or subsequent test experience. While silencing all four populations reduced hard-wired courtship toward virgin females, behavioral differences arose when GRNs were silenced during training versus testing, or when males courted flies with different pheromone blends. Thus individual GRNs within a population control different aspects of behavior; a result which parallels the organization and drive of other gustatory behaviors like feeding and avoidance. To identify potential courtship circuits within the populations silenced, the behavioral results were compared across courtship contexts to generate "courtship channels:" hypothetical pathways connecting courtship behaviors to sub-sets of GRNs. One channel identified suggests courtship conditioning may not be associative in the classical formulation: males with this channel silenced during training suppress courtship selectively depending on the pheromones encountered during testing. An alternative theory, called the "independent channel" model, explains this and other long-standing anomalous results by proposing that courtship suppression is produced by experience modifying the efficacy of individual courtship channels to drive courtship.