Diversity in neural firing dynamics supports both rigid and learned hippocampal sequences

Science. 2016 Mar 25;351(6280):1440-3. doi: 10.1126/science.aad1935.


Cell assembly sequences during learning are "replayed" during hippocampal ripples and contribute to the consolidation of episodic memories. However, neuronal sequences may also reflect preexisting dynamics. We report that sequences of place-cell firing in a novel environment are formed from a combination of the contributions of a rigid, predominantly fast-firing subset of pyramidal neurons with low spatial specificity and limited change across sleep-experience-sleep and a slow-firing plastic subset. Slow-firing cells, rather than fast-firing cells, gained high place specificity during exploration, elevated their association with ripples, and showed increased bursting and temporal coactivation during postexperience sleep. Thus, slow- and fast-firing neurons, although forming a continuous distribution, have different coding and plastic properties.

Publication types

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

MeSH terms

  • Action Potentials
  • Animals
  • Hippocampus / cytology
  • Hippocampus / physiopathology*
  • Learning / physiology*
  • Male
  • Maze Learning
  • Neuronal Plasticity
  • Pyramidal Cells / physiology*
  • Rats
  • Rats, Inbred LEC
  • Sleep / physiology