The genes and neural processes underlying memory formation are highly conserved across animal groups, and the powerful genetics in the fruit fly allows for a detailed investigation of the neural basis of memory formation. A single-fly taste memory assay has been developed that allows for interrogation of the neurons that encode memories. Genetic approaches in the fruit fly will be employed to precisely identify the neurons involved in taste memory. Associative taste memory depends on dopamine, a neurotransmitter involved in reward and memory formation in many animal phyla. Functional imaging approaches will be used to determine the sensory cues that activate dopamine neurons, and how activity of memory-relevant neurons changes following memory formation. This work will allow for the generation of a cellular model of memory formation that will be improve understanding of learning and behavioral plasticity throughout the animal kingdom. In addition to the scientific goals, this research program will increase accessibility to science for underrepresented scientists, undergraduate researchers and the broader community at the University of Nevada, Reno. This project will involve high school students, outreach work at the Nevada Discovery Museum, and undergraduate curriculum development. Additionally, the investigators will organize monthly hands-on events about scientific research aimed at elementary and middle school students.
While the neurotransmitter dopamine is a conserved regulator of associative memories, the cellular and neural principles through which it mediates memory are not yet well understood. This work combines a novel behavioral assay for taste memory with genetic and optogenetic tools to identify and characterize individual neurons regulating taste memory. For the first time, a novel genetic toolkit of GAL4 lines allows for direct manipulation individual populations of dopamine neurons, up to level of single neurons. The aims of this research will precisely identify the PPL1 dopamine neurons modulating aversive taste memory; examine the connectivity of PPL1 dopamine neurons underlying aversive taste memory; and employ physiological (GCaMP imaging) analysis of PPL1 dopamine neurons to examine plasticity within these neurons. Taken together, this research will identify neural circuitry required for taste memory and the physiological changes that occur in this circuitry during memory formation.
