Mar 13 2025

LIN Seminar: “The mechanisms that drive the neural dynamics of memory” by Mark Sheffield (University of Chicago)

March 13, 2025

4:00 PM - 5:00 PM

Location

SELE 4289

Please join us March 13th at 4pm in SELE 4289 for a LIN Seminar featuring Dr. Mark Sheffield (University of Chicago)

Sheffield Lab

Host: Alex Keinath

Abstract: Hippocampal representations must simultaneously encode new experiences while preserving stability for future memory retrieval. Using two-photon calcium imaging, optogenetics, and computational modeling, we identify a coordinated framework in which regional specialization, hemispheric asymmetry, and behavioral-timescale synaptic plasticity (BTSP) interact to shape hippocampal dynamics. Using place cells and their place fields as a neural correlate of memory, we find that CA1 rapidly forms new place fields that shift progressively with ongoing experience, whereas CA3 representations emerge more gradually and remain more stable. This difference is governed by BTSP, which drives both place field formation and continuous shifting in CA1 but operates more sparingly in CA3, providing a stable spatial scaffold. However, lateralized CA3 inputs differentially regulate CA1 place field dynamics at different phases of learning: right CA3 dominates during initial novel exposure, accelerating encoding, while left CA3 dominates later to sustain CA1 long-term stability by reinforcing spatial representations with ongoing experience. This asymmetric input organization suggests that CA1 spatial information is controlled by distinct sets of CA3 inputs at different phases of learning and uses BTSP to transform these inputs into new and dynamic CA1 place fields that balance flexibility and stability. Our findings provide a mechanistic account of how hippocampal circuits transform experiences into stable, yet adaptive, spatial representations.

Contact

Emily Beaufort

Date posted

Aug 23, 2024

Date updated

Feb 13, 2025