Probing form and function of memory representations in the hippocampus of memory expert birds

Project Summary/Abstract Mental disorders that affect the hippocampus disrupt people’s ability to form one-shot memories. My goal is to lead an independent lab, linking biological properties of hippocampal neurons to the ability to perform memory- guided cognitive behaviors. To map cognitive behaviors to their underlying neural mechanisms, my lab will perform theoretical analyses and simulation of state-space models of cognitive behaviors, implementing these models in a recurrent network architecture with learning rules that match biological plasticity rules (Aims 3a, c). To precisely characterize memory-guided behaviors at real-world complexity, my lab will apply state-of-the-art behavioral tracking techniques in natural settings to foraging behavior of wintering birds, chickadees and sparrows (Aim 3b). As a theorist, I will actively collaborate with experimentalists, drawing on my experience recording from the brain in animals performing cognitive tasks. My postdoctoral work in the Aronov lab, at Columbia University’s Zuckerman Institute, focuses on neural activity underlying a hippocampus-dependent one-shot memory behavior, food-caching, in the model system chickadees, caching birds with extreme memory abilities. I developed new methods for recording large populations of neurons in the chickadee hippocampus while they cache and retrieve food, and methods for precisely tracking their caching behavior (Aim 1a). Probing the hippocampus at moments of caching, I found a new mode of hippocampal activity patterns (Aim 1b), which is reactivated when birds return to retrieve food (Aim 1c). To compare this one-shot mode to representations of consistent environmental features, I am reproducing, in food-caching birds, findings from rodents showing changes to place cells at consistent reward zones, and comparing this to one-shot representations of food-caching (Aim 2a). I am developing a theoretical state-space model that explains both one-shot and consistent representations in the hippocampus (Aim 2b), incorporating hippocampus-inspired neural mechanisms (Aim 2c). Here, I outline a training plan to expand my skills and experience to lead an independent lab doing a combination of theoretical and real-world behavioral studies. I will deepen my training in theoretical methods working with my co-mentor Prof. Larry Abbott, and through affiliation with the Columbia Center for Theoretical Neuroscience. My training in tracking real-world behavior will be guided by my collaborator Prof. Vladimir Pravosudov, the leading pioneer in tracking real-world chickadee behaviors, with an extended visit to his Cognitive and Behavioral Ecology Lab and field sites. For additional training designing and fabricating custom equipment, I will work with Dr. Tanya Tabachnik, who heads the Advanced Instrumentation Core at ZI. This additional training, with instrumental support from the K99/R00 award, will prepare me well, and make me a highly competitive candidate for tenure-track faculty positions.