The neural basis of path integration memory in insects
Many animals make direct trips back to their homes after tortuous foraging trips using a navigational strategy called path integration (PI). During PI, sensory information for direction and distance measurements are used to calculate the straightest path back to home. While PI has been well studied behaviorally, the neural basis of vector memory formation is unknown in any animal. Here, I will combine behavior and physiology to demonstrate PI and the neural basis for vector memory formation in bumblebees. First I will develop real-world behavioral arenas to demonstrate that walking bees use PI. Next, I will use virtual reality to mimic the real-world arenas, demonstrating PI behavior in stationary bees. I will also develop electrophysiological methods to record from neural centers of interest in the brains of restrained bees. Finally I will combine the physiology refined in restrained bees and the PI behaviors in virtual reality to physiologically record from the brains of bees actively performing PI. From these experiments, I will ideally be able to measure the buildup of PI memory and observe how PI memory is used for steering during the homebound part of the foraging trip. From the proposed work, the neural basis of PI will be uncovered for the first time. Navigational feats extending past acquiring and following a home vector may be investigated in the future using the same methods. Results from this work have the potential for gains in applications such as robotics. Finally, during my fellowship, I will gain neuroanatomical and functional tools that will aid in my future research plans to investigate the neural basis of navigation behaviors of mantis shrimp, animals which exhibit similar navigational strategies to those of insects, such as bees, while underwater, with the end goal of uncovering the evolutionary origins of complex, widespread navigational strategies in arthropods and potentially other animals as well.