Non-local computations in hippocampal circuits: neural mechanisms (360G-Wellcome-212281_Z_18_Z)

The overall goal of this proposal is to build a neural-level understanding of how non-local cortico-hippocampal communication mediates memory consolidation and spatial computations. The well-studied network of spatially modulated neurons in the hippocampus and associated regions provides the pre-eminent cellular-model of memory for events and places. However, the activity of these neurons mainly encodes local information, that is, the current configuration of an animal in its environment. Work conducted by us, and others, have identified transient reactivations of hippocampal neurons and cortical counterparts as a key mechanism supporting systems consolidation and spatial planning. These brief ‘non-local’ events provide a means by which remembered experiences can gradually update memory networks, equally they are theorised to support the calculations necessary for route planning. Our aims are: 1) to understand how hippocampus and cortex interacts during reactivations; 2) determine how reactivated information affects existing representations; 3) precisely define the spatial computations that guide navigation; 4) investigate how neuromodulation controls the occurrence of reactivations. To this end, our approach is to combine computational modelling, machine learning, and state-of-the-art experimental techniques. Developing a basic understanding of these processes opens the way to understand how they fail in disease and may ultimately deliver tremendous therapeutic benefits.