CAMBRIDGE, Mass., Dec. 20 (UPI) -- U.S. researchers say they've determined waking experiences are replayed in multiple parts of the brain in a coordinated fashion during sleep.
Matt Wilson and colleagues at the Massachusetts Institute of Technology recorded neural activity in the hippocampus and visual cortex of rats during a part of the sleep cycle called slow wave sleep and during intervening sessions of awake activity, which included time spent running on a track.
Previous research by the same group had shown hippocampal activity during slow wave sleep often recapitulates sequences of activity produced when the rat traverses a path during waking. The function of such replay remains unclear but it has been suggested to be important for learning and memory, perhaps by solidifying memories of events experienced during waking.
The authors report similar replay activity is also observed in the visual cortex, and that replays in the hippocampus and visual cortex tend to occur at the same time.
The researchers say their findings suggest memory representations of the same event are reactivated during sleep across multiple brain areas.
The study appears in the January issue of the journal Nature Neuroscience.
