Abstract
Associative learning underlies much of animal behavior, explaining why dogs salivate upon smelling food or why we check our phones even without notification. Operant learning is a subset of associative learning and pairs behaviors with reinforcing stimuli. Additionally, it has significance in treatment of chronic pain, anxiety, and OCD. Drosophila melanogaster serve as an excellent model organism for studying the cellular basis behind behaviors and diseases, sharing many of the same diseases-causing genes with humans. While there has been extensive study in learning in Drosophila, little work has been done using pure operant paradigms. We developed a novel, high-throughput, positive-valance paradigm for operant conditioning, training flies to develop a turning bias towards sugar. Using this apparatus, we found a link between flies sleeping early in training and a significant change in learning. Using yoked-controls and sleep induction, we determined that the sleep-learning link is not causal in either direction, but early sleep is necessary for learning. We also screened flies homozygous for one of two isotypes of the foraging gene, rover (for[R]) and sitter (for[s]), as well as a known learning-deficient mutant, dunce (dnc[1]). We found that dnc[1] flies cannot learn this task, suggesting positive-valance operant learning is mediated through a cAMP-dependent pathway. Furthermore, while sitter flies cannot learn this task, rovers do, but show a revealed preference against sugar, implicating the foraging gene in operant learning. Ultimately, we have shown that this novel paradigm is capable of operantly training flies and shed insight onto possible mechanistic pathways.