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Neural Ensemble Mechanisms of Learning and Memory

    Research in the Foster laboratory focuses on how large populations (or “ensembles”) of neurons encode and process information in awake, behaving animals. We use high density tetrode recording techniques to investigate the activity of neural ensembles during tasks which incorporate a variety of learning, memory, inference, planning and decision making demands.

    Currently we are interested in how hippocampal ensembles in rodents process navigationally relevant information. We have found that precise sequences of neurons are activated repeatedly during behavior, reflecting memory for immediately preceding spatial experience.

    We are seeking to determine: (a) the cellular and molecular basis of this sequential activation, and how it relates to synaptic plasticity mechanisms; (b) the functional capabilities of sequential activation, particularly in terms of inferring and planning navigationally relevant trajectories; and (c) the functional relevance of hippocampal sequential activation in guiding behavior, particularly in terms of how the hippocampus interfaces with brain regions involved in reward learning and reward-based decision making.

    Our work has potential clinical relevance for the many disorders that severely affect the hippocampus, including Alzheimer’s disease and epilepsy, and those disorders that affect interfacing brain regions in the basal ganglia, such as Parkinson’s disease and Huntington’s disease, and for complex disorders such as schizophrenia which we study directly through the use of animal models.