Hippocampal Mechanisms of Episodic Memory Recall and their Contribution to Naturalistic Navigation Decisions

PROJECT SUMMARY / ABSTRACT The hippocampus is critical for episodic memory – the ability to record information about a single experience and flexibly use this information to guide future action. The hippocampus is also implicated in spatial memory and navigation, which are thought to depend on place cells. These functions are intertwined in natural behavior, as an organism recalls individual memories to guide its navigational decisions. However, the physiological mechanisms underlying the recollection of individual experiences remain unclear. It is furthermore unknown how episodic recall influences the action-selection circuits which implement navigational decisions, as well as the role of place cells in this process. I will use the food-caching behavior of black-capped chickadees as a model system to address these questions. Chickadees are known to form single-shot, hippocampal-dependent cache memories which they use to subsequently retrieve cached food items. I will identify neural signatures of episodic memory recall in hippocampal activity, and develop a computational model of the mechanisms involved (Aim 1; K99). To determine the mechanisms mediating memory’s interactions with decision making, I will characterize neural tuning in areas downstream to the hippocampus which play a role in action selection, including the lateral septum and nucleus accumbens (Aim 2; R00). The chickadee hippocampus exhibits many functional and anatomical homologies with mammalian hippocampus, so results will reveal fundamental mechanisms broadly shared across vertebrates. Episodic memory and hippocampal function contribute significantly to human quality of life, and are disrupted by conditions like Alzheimer’s disease, so results will assist future technology development to improve and preserve memory abilities in health and disease. Candidate and Career Goals: I intend to obtain a tenure-track faculty position where I will establish an independent research lab. I will study episodic memory and decision making using food-caching birds, with a focus on interactions between hippocampal and subcortical brain areas. Career Development Plan: I will be trained by primary mentor Dr. Dmitriy Aronov to develop novel behavioral paradigms and electrophysiological techniques in food-caching birds. My co-mentor Dr. Larry Abbott will train me in developing computational circuit models of hippocampal function. I will also receive training from co-mentor Dr. Jesse Goldberg in preparation for studying subcortical areas involved in motor control and their interactions with hippocampus. In combination with the support of research and professional development opportunities at Columbia University, this training will make me a highly competitive candidate for research positions.