Neuron
Volume 63, Issue 4, 27 August 2009, Pages 497-507
Journal home page for Neuron

Article
Hippocampal Replay of Extended Experience

https://doi.org/10.1016/j.neuron.2009.07.027Get rights and content
Under an Elsevier user license
open archive

Summary

During pauses in exploration, ensembles of place cells in the rat hippocampus re-express firing sequences corresponding to recent spatial experience. Such “replay” co-occurs with ripple events: short-lasting (∼50–120 ms), high-frequency (∼200 Hz) oscillations that are associated with increased hippocampal-cortical communication. In previous studies, rats exploring small environments showed replay anchored to the rat's current location and compressed in time into a single ripple event. Here, we show, using a neural decoding approach, that firing sequences corresponding to long runs through a large environment are replayed with high fidelity and that such replay can begin at remote locations on the track. Extended replay proceeds at a characteristic virtual speed of ∼8 m/s and remains coherent across trains of ripple events. These results suggest that extended replay is composed of chains of shorter subsequences, which may reflect a strategy for the storage and flexible expression of memories of prolonged experience.

SYSNEURO

Cited by (0)

2

These authors contributed equally to this work