Jason Climer - Memories in motion: using mouse virtual reality to probe representational drift

Jason Climer - Memories in motion: using mouse virtual reality to probe representational drift

Jason Climer, University of Illinois Urbana-Champaign

Abstract:

For decades, the dominant model of memory has been that the neurons encoding a memory are fixed for its lifetime. Hippocampal place cells, which fire when an animal visits a specific location, were thought to be the clearest example. Calcium imaging changed this picture when it allowed us to follow the same neurons over days and weeks: the neural representation for the same space slowly evolves over time. This phenomenon, called representational drift, raises a basic question about how memory can survive when the neurons holding it keep changing. Virtual reality is what makes this question answerable. In the real world we cannot control what an animal sees, smells, or does from day to day. In my lab, mice run through virtual environments while we image hundreds of neurons, and under these controlled conditions drift persists, so it is coming from the brain rather than the world. I will discuss ongoing work in which mice traverse procedurally generated environments, along with new paradigms for the inputs to place cells and memory stability in health and disease.

Speaker Bio: 

Jason Climer’s research asks how the hippocampus stores and updates memories over time, with a focus on representational drift in place cell populations. The lab's central hypothesis is that forgetting is adaptive, and that drift is its signature rather than a failure of the system. To test this, the lab combines two-photon calcium and glutamate imaging with virtual reality tasks in head-fixed mice. He earned his PhD with Michael Hasselmo at Boston University's Center for Memory and Brain and completed postdoctoral training with Dan Dombeck at Northwestern University.