Neural Circuits for Spatial Navigation

The hippocampus and associated brain structures are known to simultaneously represent a subject’s ongoing location, directional heading and movement-related correlates during active locomotion. Of these areas, the hippocampus appears to play a central role in navigation because, at fine temporal scales, its spatial representations also predict immediate upcoming locations much like a neuronal GPS. Besides tracking the subject’s current position, recent evidence demonstrates that during pauses in navigation the hippocampus encodes sequences of locations that correspond to trajectories that the subject either followed to arrive to its current position or will follow to complete its path to a goal location. Thus, the hippocampus is also able to provide the required representations to support planning which is an essential component of intelligence. In this project we study the hippocampus along with brain structures implicated in navigation to identify whether and how they interact to solve one of the Center’s challenges of “Where did I come from?” and “Where am I going to?”. We focus our attention on the anterior dorsal thalamus, which acts as a neuronal compass by encoding the subject’s current heading direction, and the retrosplenial cortex, which receives and processes egocentric and allocentric spatial information during navigation. We employ large-scale, multi-site recording techniques to simultaneously sample the activity of several brain structures during the execution of different behavioral tasks. We exploit different decoding and computational strategies to interpret ensemble spiking patterns to help us uncover how spatial information is represented and potentially communicated along these structures to enable spatial planning.