Distinct place cell dynamics in CA1 and CA3 encode experience in new environments

Nat Commun. 2021 May 20;12(1):2977. doi: 10.1038/s41467-021-23260-3.

Abstract

When exploring new environments animals form spatial memories that are updated with experience and retrieved upon re-exposure to the same environment. The hippocampus is thought to support these memory processes, but how this is achieved by different subnetworks such as CA1 and CA3 remains unclear. To understand how hippocampal spatial representations emerge and evolve during familiarization, we performed 2-photon calcium imaging in mice running in new virtual environments and compared the trial-to-trial dynamics of place cells in CA1 and CA3 over days. We find that place fields in CA1 emerge rapidly but tend to shift backwards from trial-to-trial and remap upon re-exposure to the environment a day later. In contrast, place fields in CA3 emerge gradually but show more stable trial-to-trial and day-to-day dynamics. These results reflect different roles in CA1 and CA3 in spatial memory processing during familiarization to new environments and constrain the potential mechanisms that support them.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior Observation Techniques
  • Behavior, Animal / physiology
  • CA1 Region, Hippocampal / cytology
  • CA1 Region, Hippocampal / diagnostic imaging
  • CA1 Region, Hippocampal / physiology*
  • CA3 Region, Hippocampal / cytology
  • CA3 Region, Hippocampal / diagnostic imaging
  • CA3 Region, Hippocampal / physiology*
  • Craniotomy
  • Intravital Microscopy / instrumentation
  • Intravital Microscopy / methods
  • Male
  • Mice
  • Microscopy, Confocal / instrumentation
  • Microscopy, Confocal / methods
  • Models, Animal
  • Optical Imaging / instrumentation
  • Optical Imaging / methods
  • Place Cells / physiology*
  • Space Perception / physiology*
  • Spatial Memory / physiology*