Remapping across time, space and region

We take it for granted that we can distinguish similar events yet still group them together as being similar. Two concerts, for example, offer similar sensory experiences: They take place in large rooms with many people, typically with dimmed lights and loud music. But there are also many differences — the design of the space, the identities of the crowd, and the quality of the music. Our brains face the challenging task of learning to group experiences by similarities — they were both ‘concerts’ — yet still distinguish them as two different events. One way that neural circuits might accomplish is this is via remapping, where the same neuron that encodes a memory, might, at a different time, encode location, time or sound. To gain insight into how the same neurons could encode multiple things, we will record brain activity in rodents and monkeys as they navigate different landscapes, such as an open field where they forage for food or a maze with multiple decision points. We will use novel recording technology capable of recording from the same neurons over time to determine how individual neurons shift their activity based on the environment and the task — in essence, the phenomenon of remapping. For example, the activity of the same neuron might reflect the rat’s heading direction when moving slowly, but its speed when moving quickly. In this case, the neuron has been remapped from direction to speed.  We believe a similar process underlies how one neuron can be remapped from one memory to another. With this data, we can reconstruct the behavior of large neural circuits in brain areas involved in memory and navigation. Our group will collaborate with several other experimental and computational labs to develop the techniques and mathematical tools to gain insight into this fundamental brain process.