Research

Preplay of Future Place Cell Sequences and Spatial Trajectories

Temporal sequences of firing recorded during sleep (a) correspond closely to novel place cell firing sequences observed when naïve animals subsequently explore a new environment (b). Similarly, Bayesian decoding of temporal sequences during sleep reveals spatial trajectories (c) that match the future trajectory of the animal on the novel track (d).

Learned information is not encoded in isolation, but is integrated within a network of preexisting knowledge stored in patterns of neuronal ensemble functional connectivity. Our immediate goal is to investigate:

  1. How these patterns emerge and develop
  2. How are they utilized in behavior
  3. How are they disrupted in neuropsychiatric diseases

The hippocampus, a brain structure initially implicated in rapid learning and formation of episodic memory, is now recognized to encode internally-generated spatial-temporal sequence representations. Its dysfunctions have resulted in anterograde amnesia, impaired imagining of new experiences, and hallucinations. Achieving our goal will be facilitated by our use of electrophysiological recordings of ensembles of neurons in behaving mice and rats, optogenetic manipulation of neurons, optical imaging of neuronal ensembles, and computational methods for decoding neuronal population activity.